The aim of this paper is to discuss a recent find of a late medieval light field cannon that was discovered in the course of excavations at the Old Castle in Grodno, Belarus. Although a great deal is known on late medieval firearms and early modern period, also concerning Central and Eastern Europe [1-4], the state of research on their manufacturing technologies is still unsatisfactory. Studies usually concern artefacts from single archaeological sites (e.g.,[5-6]), certain kinds of firearms [7-8], technology of firearms in a given country , or individual artefacts (e.g.,[10-11]). Sometimes results of technological examinations are integrated within regional studies on early gunpowder weapons (e.g.,). Therefore, each technological study of medieval or early modern period firearms can be a chance to significantly broaden our knowledge in this field. In this case, the authors of this paper were offered an opportunity to carry out technological examinations of this newly discovered gun from Grodno. Apart from metallurgical analyses, the gun was dealt with in a broad historical and archaeological context. Furthermore, it was discussed against the background of development of late medieval and early modern period firearms, also with regard to questions of manufacturing technology.
Archaeological and historical contexts
Architectural and archaeological examinations were carried out in 2014 and 2015 at the Old Castle in Grodno. They were aimed at preparing ground for restoration works (on the castle itself see [12-15]). 14 trenches were opened altogether. Trench 13 was marked out in the lookout terrace in the courtyard along a defensive wall (Fig. 1), in a location where in 18th c. plans there was a remarkable curve in the wall (for the 18th plans of the castle see ). The defensive wall next to Trench 13 was constructed on top of a medieval defensive rampart at the end of the 14th or in the early 15th c. after strong fires from the 1390s (on this phase of the stronghold see ). In the 1580s, the defensive wall was repaired and in the 1930s it underwent conservation works. Buildings were constructed in this area in the 16th-18th c. [12; 13]. Due to this, the upper layers in Trench 13 were to a great degree mixed. The trench was trapezoid and its dimensions were 6.5 x 4 m. Cultural Layers 1 and 2 (sand padding under the pavement) in this trench were formed in result of land management works after excavations in the 1980s . Both Layers 3 and 4 contained brown soil with brick rubble, fragments of roofing tiles, small vessel shards from the 16th-18th c., only Layer 3 showing presence of numerous pieces of 20th c. garbage. Layer 5 contained sandy clay, with numerous fired clay lumps. Cannon remains were found at Layer 5, adjacent to a 70x40-45 cm charcoal deposit showing thickness varying from 3 to 7 cm and located at a distance of approximately 14 cm from the northern side of the wall (Fig. 2). Numerous remains of melted copper were found adjacent to the cannon remains. A c. 40 cm thick layer of brown soil with traces of fire was found beneath the charcoal deposit. Pottery finds that were discovered there were dated to the second half of the 14th c. Beneath this layer there were cultural strata that were related to the construction of a defensive rampart in the 12th-13th c. (on this early phase of the stronghold see ; all data concerning the find context was kindly provided by Natalya A. Kiziukevič, Grodno State Historical and Archaeological Museum, personal communication, 20 April 2020).
In the period between the last quarter of the 14th and the early 15th c. Grodno and its vicinity became an area of intensive military operations. These were a result of political contacts between Grand Duchy of Lithuania and the Teutonic Order, with special stress on complex relationships between the Lithuanian Duke Jogaila (since 1386 Władysław II Jagiełło King of Poland) and his cousin Duke Vytautas. In Summer 1378, the Order launched an expedition against Lithuania and devastated the region of Podlachia with the strongholds of Brest and Grodno [16 p593, 597; 17 p107; 18 p48]. In 1384, Vytautas abandoned the Order’s side and received in return the strongholds of Grodno, Brest, Drohiczyn, Mielnik as well as other territories [18 p89-93].
However, in 1389 Vytautas rose against Władysław and attacked Vilnius. After failing, he allied again with the Order in 1390 and gave it the region of Samogitia [18 p128-133]. In January 1390, the Order launched another military expedition to Lithuania and seized several strongholds, including Grodno and Brest. Władysław soon prepared a counterattack, and on 16 April 1390, Grodno was taken by Polish-Lithuanian troops. Interestingly, both Polish and Teutonic sources mention the use of firearms by the besieging forces [16 p640-641; 17 p162-163; 19 p162-163; 20 p180-182; see also 18 p134]. On this occasion it must be emphasised that for this period the use of firearms in this part of Europe was not limited to Teutonic or Polish troops. The Teutonic chronicler Wigand von Marburg frequently mentions cases of application of the new weapons by the Lithuanians as well [16 p613, 622, 633].
In November 1391, a new Teutonic expedition was led by the new Grand Master Konrad von Wallenrode as an ally of Duke Vytautas. In early December, the castle of Grodno was taken again by the Order’s forces and was ceded to Vytautas. Wigand von Marburg said that firearms had been used by both parties (fiunt varii conflictus bombardarum, sagittationes diverse) [16 p646-647; 19 p174-176; see also 18 p137-138 and 21 p166].
In 1392, it came to another reconciliation between Vytautas and Władysław. In October, the Order invaded Vytautas’ lands and in early January 1393 Grodno was taken and razed to the ground. Wigand von Marburg mentioned again an extensive use of artillery by the besiegers (impugnant cum lapidibus bombardarum castrum) [16 p649; 17 p185; 19 p185; 22 p623; see also 18 p172 and 21 p166]. The surroundings of Grodno became a basis of new Teutonic expeditions in early 1394 [16 p650-652; 19 p191; 22 p627; see also 18 p173].
On 23 April 1398, a treaty was made between the Order and Vytautas. According to it, the region of Samogitia became part of the Order’s possessions [18 p179-181]. However, after another reconciliation between Vytautas and Władysław, in Spring 1401 it came to an anti-Teutonic uprising in Samogitia. The Order responded with military actions and in February 1402 Grand Marshall Werner von Tettingen ravaged the vicinity of Grodno [19 p256, 264-265; see also 18 p253-255].
On the basis of the archaeological stratigraphy and the historical evidence, it can be assumed with reasonable certainty that the cannon found in Layer 5 may have been in use during the Polish-Lithuanian-Teutonic conflicts in the last quarter of the 14th c. However, it seems much more complex to decide to which side of the hostilities it may have belonged.
Description and classification of the artefact
The artefact in its present shape was strongly affected by fire (Fig. 3A). The find consists of a main body and three detached fragments which must have originally belonged to the chase. The main body is a single cylinder that includes the breech part and the chase part, the latter being only partially preserved. Thus, the original shape of the cannon cannot be fully reconstructed. In the back part of the breech there is a primitive touch-hole, with no traces of a priming pan. A convex cross decorates one of the surviving metal fragments. This fragment perhaps comes from the muzzle and the cross may have served as a primitive aiming device (Fig. 3B). No lifting handle survived and no traces of it can be seen on the cannon’s surface. A speculative reconstruction of the gun and its cross-section (as it can be proposed on the basis of similar surviving guns that are discussed below) can be seen in Fig. 4. The metrical data of the artefact are the following:
- total weight (surviving): 13.85 kg
- total length (surviving): 287 mm
- length of the chase (surviving): 84 mm
- length of the breech: 203 mm
- internal length of the powder chamber: c. 120 mm
- diameter of the powder chamber: c. 68 mm
- length of the bore (surviving): 206 mm
- external diameter at the breech: 122 mm
- external diameter at the muzzle (surviving): 221 mm
- internal diameter at the muzzle (calibre): c. 155 mm
- distance between the touch hole and the breech base: 82 mm
- diameter of the touch hole: 11 mm
- estimated weight of the projectile: c. 5260 g (granite)
- putative weight of the gunpowder’s charge: c. 260 g (c. 1:20 proportion between the charge and the projectile, see [23 p14 or 24 p163]) or c. 400 g (assuming a 1:13 proportion, as proposed in [25 p28])
On the basis of its calibre it can be assumed that stone projectiles were used for the gun, which thus could be termed a Steynbüchse [21 p157; 23 p12; 24 p144]). A gun of such a size can be classified as a light field cannon. Such cannons could be either transported on carts and then placed on wooden stands or could be mounted on wheeled carriages [2 p84-92; 21 p159-160; 24 p60-61]. Schmidtchen states that in the case of early stone ball cannons a usual length proportion between the calibre and the powder chamber was c. 1:2 [23 p14]. In this case, it is merely 1: 1.3, which may support an assumption of an early chronology of the Grodno cannon. A relative narrowness of the powder chamber (c. 68 mm in this case) in relation to the calibre (c. 155 mm) is also considered a feature of early cannons of such type. This was aimed at securing a proper concentration of the explosion’s impact and thus a better compression of the gunpowder charge [23 p14]. The archaeological context clearly implies a late 14th c. chronology of the cannon and this also receives support from analogous artefacts which are dealt with below. Nevertheless, it should be borne in mind that such cannons may have remained in use for much longer, as discussed later on in this paper.
Early firearms in Rus
Not much is known on the early history of firearms in Rus. The first mentions in written sources come from the late 14th c. It was recorded that defenders of Moscow used firearms against the Mongol siege in 1382. What was mentioned were “tyufyaki” (тюфяки) and large guns (великiи пушки) [26 p44], or simply guns (поушки) in another version of the report [27 p331-332; 28 p74]. The term “tyufyak” probably refers to lighter guns, which is also implied by the context. Another interesting record comes from 1389 and says that “in this year guns were brought from Germany” (ТогожелѣтаизъНѣмецьбынесошапушкы) [29 p444]. In 1394, guns (пущичи) were mentioned during the siege of Pskov by Novgorod Veliky’s forces [30 p194]. In 1408, the Mongol Khan Edigey demanded Prince Ivan Mikhailovič of Tver to support him against Moscow with “guns and tyufyaki” (съпушками, исътюфяки) [26 p83; 31 p220-222; 32 p77-78]. McLachlan supposes that “tyufyaki” were large handgonnes and mentions 17th c. examples with calibres between 40 and even 85 mm [3 p41; see also 32 p85-87]. Wilinbachow assumes that the very term is of Eastern origin (cf. Persian tufang/tupang meaning “pipe” or “tube”, or Turkish tufenk, which may have stood for early flamethrowers). He rejects an assumption that “tyufyaki” were cannons which were only used for firing shots. Instead, he proposes that full-sized projectiles were also used for such guns, which is also supported by later 17th c. records mentioning large stone, lead and iron ammunition. Interestingly, these records mention “tyufyaki” that were manufactured both of iron and from copper. According to Wilinbachow, “tyufyaki” were short-barrelled cannons analogous to early Western European bombards and they could mounted on wheeled carriages [33 p226-230, 232; see also 34 p28]. Wilinbachow also maintains that the appearance of early firearms in Rus was due to Western European and not Eastern (chiefly Mongol) influence [33 p218-220]. On the other hand, as in Kirpičnikov’s opinion the earliest terms referring to firearms in Rus were of general Slavic (“puška”; this in fact comes from German “Büchse” and Latin “pixis” – G. Żabiński) and of Near East origin (“tyufyak”) respectively, this researcher supposes that the new weapon reached the Rus lands from two directions, that is, from the West and the East. According to this scholar, the Western direction was more significant [32 p78-79]. In 1426, Lithuanian troops of Grand Duke Vytautas used guns (пушки) during an expedition against Pskov [35 p25; see also 32 p79]. An interesting mention is known from 1427 concerning an expedition of Vytautas against Novgorod Veliky. It says that Lithuanian troops took “guns, tyufyaki and handgonnes” (пушки, и тюфяки, и пищали). Оne of the guns, called “Galka” was so heavy that it was pulled by a team of 40 horses [26 p94; for a similar set of firearms mentioned in 1450 see ibid. p122-123; see also 24 p214-215 and 33 p227]. In 1444, guns (пушки) were used by both sides during the Teutonic siege of the fortress of Yam (Kingisepp) defended by Novgorod forces [36 p185; see also 31 p222]. In 1447, guns (пушки) sent by Duke Boris Alexandrovič of Tver were used during the siege of Uglič by Grand Duke Vasily II of Muscovy. In the same year, Duke Boris successfully applied guns in the siege of Ržev [29 p493; 31 p221-221]. Furthermore, from 1447 there comes a mention of the use of guns by the Novgorodians in a naval battle [36 p185; for similar events from 1459 see 30 p218; 31 p222]. A 1667-1671 description of firearms in Smolensk mentions a “copper piščal on a wheeled carriage, cast in Russia, whose length was 2 aršins and 2.5 veršoks” (c. 153 cm) (Пищаль медная, в станку на колесах, Русского литья, длина два аршина полтрети вершка). It was provided with a Russian inscription, saying that it was cast in 1483 by a master Yakov. Its weight was 16 puds, or c. 262 kg [37 No. 51, p304; see also 31 p225-226; 32 p81; 33 p232]. This record is coherent with an opinion that gun foundries came into existence in Rus in the late 15th c. [3 p41; 31 p223 ff; 32 p80-81].
Archaeological finds of early firearms from this part of Europe are not very numerous. One of the earliest artefacts is an iron-forged mortira found near Stary Krym in Crimea in 1885 (Fig. 5.1). This gun is dated to c. 1375-1425 and may be of Italian provenance, due to a strong presence of the Genovese in the peninsula. This gun is 44 cm long, its calibre is 8.1 cm and its weight is believed to be merely 11.5 kg. Another similar artefact of the same chronology is known from Ržev in Russia (Fig. 5.2). This gun is iron-forged, its total length is 46 cm and the calibre is 12.2-12.7 cm [34 p28, Fig. 4; 38 p59-60, Fig. 1; 39 p32, 34, cat. No. 1, Pl. 1]. As it can be seen, these guns are quite similar to the Grodno cannon, although they are iron and not copper alloy. A very interesting gun was discovered in the vicinity of Stary Krym in Crimea in 1966 and is now stored in the Museum of Antiquities in Feodosia (Fig. 6). Its total length is 895 mm and its calibre is 148 mm. This cannon is made of bronze and it is supposed that it may be of mid-15th c. Genovese origin. On the other hand, its Turkish (or local?) provenance cannot be excluded, either. The chase of the cannon is decorated with what seems to be an “Eastern” ornament (inscription?) [34 p27-28, Figs.1-2; 38 p60-62, Figs. 3-5]. Furthermore, a possibly mid-15th c. veuglaire was found in 1911 in the River Narva (it is stored now in the Military-Historical Museum of Artillery, Engineers and Signal Corps in St. Petersburg, inv. No. 1/1) [31 p222-223, Fig. 1].
An early handgonne dated to c. 1375-1450 was found somewhere in Central Russia and is now stored in the Ivanovo State Museum of History and Local Lore. A similar gun, dated to c. 1400 and possibly related to Rus-Mongol conflicts in the 1420s-1440s, was discovered in the River Lukh in the Vladimir Region [32 p87-88, Fig. 41, Pl. 28; see also 40 p42, Figs. 28 and 33]. Two fragments of hand-held gun barrels and an iron fitting of such firearms that may be dated to the late 15th-16th c. were found in the fortresses of Staraya Ladoga and Orešek in North-Western Russia [41 p220-224, Figs. 2.1-3].
One of the most obvious analogies is an early 15th c. light field Teutonic cannon from Kurzętnik (Kauernick) in Western Prussia (now North-Eastern Poland) (Fig. 7). This gun shares the same construction design with the cannon from Grodno, that is, a narrower breech and a wider chase. Its dimensions are the following: total length 507 mm, calibre 135 mm, length proportion between the calibre and the powder chamber 1:1.7, weight 42.28 kg. Technological examinations have demonstrated that this cannon was cast using copper with antimony (Sb) and lead (Pb) impurities. Regrettably, no quantitative analysis of the elemental content was carried out [21 p155-162, Figs. 1-9, p182, Fig. 37, p184-186, Fig. 38].
Attention is also drawn to a late 14th-early 15th copper alloy cannon of possibly Bosnian origin, now in the collection of the Museum für Deutsche Geschichte in Berlin (inv. No. W 347). Its total length is 65 cm, its calibre is 14 cm, its powder chamber diameter is 5.2 cm and the weight is 80.3 kg. The chase is somewhat wider than the breech, although this difference is not that pronounced as in the case of the cannon from Grodno [2 p87; 42 p36].
A convenient analogy is also offered by a light field cannon from the collection of the Zeughaus in Berlin. This gun is dated to the 2nd half of the 15th c. and is probably related to Burgundian-Swiss conflicts from the 3rd quarter of this century. It is made from iron bars and is provided with a holder and an additional iron ring. The barrel is 80.5 cm long, its calibre is 18.0 cm while the powder chamber’s diameter is 5.0 cm. This gun is mounted on a two-wheel carriage, provided with an “aiming bracket” or a split-trail elevation [4 p310-311, No. 25].
An interesting artefact is stored in the collection of the Museum in Nový Bydžov in the Czech Republic (barrel length 53.5 cm, calibre 11 cm, powder chamber diameter 7.0 cm). The chase of this iron-forged field cannon is also wider than the breech, although the difference is not as prominent as in the case of the gun from Grodno. The chronology of the gun from the Museum in Nový Bydžov is estimated at the 1st quarter of the 15th c. [2 p85, 88-89, 366, Pl. 86, cat. No. 71; 42 p36; for other similar cannons see 2 p89; 43 p91-92, Figs. 2-3; 44 p182-187; 45 p165-176].
Another artefact which can be compared to the Grodno gun is a copper alloy field cannon from the fortress of Belgrade in Serbia. Its total length is 84 cm, the breech length is 40 cm and the calibre is 13 cm. The chase is somewhat wider than the breech. This gun can possibly be dated to the 1st half of the 15th c. and its deposition may be related to the Turkish sieges of Belgrade in 1440 or in 1456 [2 p87-88, Fig. 11; 46 p20; 47 p135, Fig. 71].
Similar guns are often depicted in late medieval and early modern period manuscripts. A good example of a light cannon on a wheeled carriage provided with an “aiming bracket” can be seen in the Anleitung, Schiesspulver zu bereiten Büchsen zu laden und zu beschiessen. from the early 15th c. (Fig. 8.1). A similar example is displayed in Das Buch von der Büchsenmeisterei, dated to the 1460s (Fig. 8.2). The same manuscript features yet another gun of this kind, but in this case it is mounted on a much more complex wheeled carriage, which seems to enable the cannon to be moved both in the vertical and the horizontal plan (Fig. 8.3). Analogous light cannons on wheeled carriages with “aiming brackets” can also be seen in the München copy of Maximilian I’s Zeugbuch from the beginning of the 16th c. (Figs. 10.4-5).
Technology of early copper alloy firearms
Barrels of early firearms in Europe were made of two basic raw materials – iron and steel [1, p13-19; 2 p105-106, 232-238; 10; 11; 43 p90], as well as from copper and its alloys [1 p11-13; 2 p214-232; 43 p90; 51 p33-34]. As regards manufacturing of copper alloy firearms, in the case of smaller cannon barrels the lost-wax or cire-perdue technique may have been applied. In this approach, the core was first prepared using a wooden shaft which was wrapped with ropes and was then covered with clay. The surface of the core was then covered with tallow and wax. In a variant of this technique, the entire core (which played the role of a so-called “false” or “counterfeit model”) could be prepared from wax. In the next stage, a clay mould was formed around the core. The mould was then fired and the wax was thus removed by melting it away through openings in the mould [2 p225-226; 9 p95]. Concerning barrels of hand-held firearms, in the end of the first half of the 15th c. a new technology on the basis of wooden models was introduced, which allowed for the serial production of barrels. Such models were then covered with clay to form the mould which was then reinforced with iron rims. After the mould had been dried, the model was removed and it was replaced with an iron core [2 p225-227].
The process of casting a large Turkish cannon’s breech during the siege of Constantinople in 1453 was described by Kritoboulos in 1467. First, the cylindrical core was prepared with the use of clay and linen. Then, a clay and linen mould was made and it was additionally strengthened using timber, wood, stones and earth. The core was placed inside the mould in such a manner that empty space for the cast metal was left (Kritoboulos’ account after [52 p186-187]).
The process of cannon barrel casting was discussed in a very detailed manner by a Sienese metallurgist Vannoccio Biringuccio in the first half of the 16th c. First, a pattern exactly reproducing the shape of the gun is prepared. This pattern is usually made on a wooden beam pivoted on trestles. The beam may be wrapped around with a rope and is covered with clay and ash. Then, a ball-shaped feeding head is prepared, which will be placed at the mouth of the gun. Next, two clay or wooden discs are made. These will be placed at both ends of the model. They will serve as sockets which will accommodate both ends of an iron core. After the trunnions are made and are fastened with nails to the pattern, they are covered with layers of ash and tallow. The next step is a preparation of the mould which is made of layers of loam, additionally reinforced with a “cage” of iron rods and bars, covered with another layer of clay. The mould is dried and heated and when the wax and tallow between the pattern and the mould are melted, the pattern is removed. A so-called collar (an iron ring with four “legs” placed crosswise) is then placed at the end of the mould in order to hold the core in the centre of the mould. The aforementioned core is made from an iron spindle covered with ash, ropes, hemp tow and a mixture of various components. Layers of clay and dung are put on until the core’s thickness roughly matches the projectile’s diameter. In the next step, the breech’s mould is prepared analogously to the barrel’s mould [53 p234-246]. Having discussed some other technical details [53 p246-249], Biringuccio deals with the casting process itself. The mould (see Fig. 9) is vertically placed in a pit in front of the furnace and the core is fixed in the middle of the mould [53 p249-260]. Some data on the alloy composition is given in an earlier chapter of Biringuccio’s book. For bronze, a usual proportion is 8-12 pounds of tin per 100 pounds of copper (i.e., 7.4-10.7% Sn and 89.3-92.6% Cu) while the best recipe for bells is 23-26 pounds of tin (i.e., 18.7-20.6% Sn and 79.4-81.3% Cu). For “all other works” the content of tin is 12 pounds (i.e., 10.7% Sn) or more [53 p210-211]. In the course of casting attention must be paid to the melting loss of material, which is usually c. 5-8%, but it may be even 10% [53 p266]. Furthermore, Biringuccio recommends to add some tin at the end of the process to make sure that the alloy will be of proper ductility and will be devoid of holes [53 p259-260]. Eventually, the gun is extracted from the pit, the clay mould and the core are removed and finishing work is carried on [53 p307-312].
Numerous fragments of clay and metal moulds for casting cannons, many loose lumps of clay and copper alloy, as well as remains of casting installations were discovered in the Teutonic Order’s capital Castle of Marienburg (Malbork) at the site of a former foundry. The maximum calibre of cannons that were cast there was assessed at c. 33-43 cm [54 p21-29, Figs. 4-6, 11; 55 p303-305, 308-311, Figs. 5-8]. Furthermore, written records from the Teutonic Order’s state in Prussia contain numerous references to gun casting [9 p99-101]. Remains of a gun foundry from the late 15th-early 16th c. were also recorded in the course of excavations at the castle hill in Buda in Hungary [56 p156, 158-165, Figs. 4-10, 12-14].
In Central Europe, numerous examples of the earliest primitive handgonnes and hackbuts from the late 14th-early 15th c. were made of copper alloys [2 p30-34, 36-37]. Copper alloy handgonnes were also in use in the 2nd-3rd quarter of the 15th c. [2 p39-41]. Interestingly, in this period there seemed to be (at least locally) a preponderance of copper and copper alloy hackbuts over iron ones [2 p47-51; 24 p100; see also 57 p113-121]. Copper alloy barrels can also be found in hand-held firearms in the 2nd half of the 15th-early 16th c. [2 p55-56, 63-64]. A preponderance of copper hand-held firearms in the first half of the 15th c. has also been suggested for other places in Europe (Frankfurt am Main or Hildesheim, see [58 p68-71, 301-304]). Perhaps this was not a universal rule. Iron hand-held firearms may have prevailed in Köln around the mid-15th c. [58 pp. 316, 454], and there may have been a sort of equilibrium between iron and copper alloy guns in Burgundy in this period [4 p217; 58 p555-556]. Interestingly, late 14th-15th c. hand-held firearms barrels from Rus were made of iron [40 p24-25, 36, 38-39].
Among the surviving specimens of one type of early light artillery in Central Europe (so-called terrace-guns) there is an almost total absence of copper alloy barrels and nearly all preserved artefacts were iron. On the other hand, written sources from the first half of the 15th c. mention copper or bronze barrels of such cannons much more frequently than iron ones [2 p78, 80-81]. Concerning light field cannons, to which the Grodno gun belongs, both iron and copper or copper alloy artefacts are known. Furthermore, copper guns are known from written sources [2 p85-92]. Among veuglaires there is a preponderance of iron barrels, although copper and copper alloy ones are mentioned by written records, too [2 p93-101]. Concerning bombards (or the largest cannons), iron and a stave-and-hoop construction were preferred in Europe [1 p20; 2 p104-106, 108-109, 232-233; 4 p204-262-267; 7; 8; 24 p. 63, 76, Tab. 2, 80-82; 42 p79-80, Tab. 1]. On the other hand, huge bronze cannons are known both from surviving artefacts and from written sources [1 p20; 2 p104-106, 108-109, 232-233; 24 p76, Tab. 2, p82; 42 p81, Tab. 2; 52]. In general, it can be assumed that in the period to the mid-15th c. copper alloy guns were more popular than iron ones [2 p213-214]. An interesting proportion between copper and iron cannons was mentioned with regard to the siege of Saint-Saveur-le-Vicomte by the army of King Charles V of France in 1375. The royal army had as many as 24 copper bombards and merely 5 iron ones [59 p156]. Copper cannons were dominant in Dijon in Burgundy in the second half of the 14th c. [58 p555-556]. However, most veuglaires in Burgundy in the period from 1417 to 1467 were made of iron [4 p234]. As regards the Italian Peninsula in the late 15th-early 16th c., iron cannons were still in use, but the significance of bronze ordnances, especially the largest ones, was constantly increasing [60 p756-770, Tab. 1]. Copper cannons in castles and towns in the south-eastern part of the Habsburg realm (present-day Slovenia) are sometimes mentioned in the afore-mentioned München copy of Maximilian’s Zeugbuch from the early 16th c. [44 p96-99; 61 p66-67; 62].
The Teutonic Order was one of the parties involved in fights over Old Castle in Grodno. Therefore, it is worth paying attention to abundant data in written sources concerning the technology of manufacture of copper alloy firearms in the Teutonic Order’s state in Prussia. Regrettably, nothing comparable is available for Poland (where firearms are first mentioned in 1383 [2 p33; 24 p14, 230; 42 p16]) or Lithuania. For the Order’s state, the first mention on the use of firearms in narrative sources comes from 1362, while the earliest inventory record is known from 1374 (21 p165; 23 p24, 26; 24 p12]. Mentions of copper guns in the Order’s accounts and inventories sources are not frequent. On the other hand, it is evident that a difference between copper and bronze guns was known to the authors of these records, as they make a distinction between kopperyne/kopperen (copper) and erynne/eren (bronze) firearms [9 p86-88]. Copper firearms in the Teutonic Order’s state were either hand-held guns or lighter cannons [9 p86; 21 p173, 178, 180].
Concerning a general pattern of use of raw materials (copper and its alloys versus iron) for gun barrels in the Teutonic Order’s state in the period between the late 14th and the early 16th c., there was a preponderance of copper and copper alloy guns over iron ones. 385 guns were recorded in written sources, and more than 65% of these were made using copper and its alloys, copper guns being more than 17% [9 p84-88, Tab. 1]. This may validate the afore-mentioned observation concerning the dominance of copper alloys in some regions of Europe in the early period of firearms development.
A preponderance of copper alloys is even more visible in manufacture and purchase of new firearms, although it must be remembered that the lion’s share of this data comes from a narrow period of the early 15th c. In this case, among 103 acquired guns, almost 80% were made using copper and its alloys, the share of copper guns being about 6.8%. A dominance of copper alloys is even more pronounced in the case of artillery (92.7% cases) and almost all the largest guns acquired by the Order were made of bronze. It has been suggested that bronze was considered the best material for the heaviest cannons by the Order, in spite of the fact that bronze was more expensive than iron. This could imply that more attention was paid by the Order’s authorities to quality issues than to economic aspects of firearms acquisition ([9 p87-92, Fig. 2; on quality issues of bronze and iron artillery see also, e.g., [60 p756-757]).
According to written sources, the Teutonic Order’s guns cast at Marienburg (Malbork) in 1401 were manufactured of almost pure copper (about 97-97.5% Cu). A rather low amount of tin (about 2.5-3% Sn) did not have much influence on its utilitarian properties. Provided that these guns were of more or less equal weight, it can be supposed that they were rather small ordnances (about 120 kg each). Therefore, their manufacturers may have assumed that such a composition would suffice to provide these guns with proper toughness. Concerning two veuglaires from 1403, the proportion of tin was much higher (almost 11% Sn). These ordnances may have been smaller than the guns from 1401 and the total weight of one cannon with three powder chambers was perhaps a bit more than 100 kg, that is, perhaps about 70-76 kg for the chase with one chamber. In this case, it could be tentatively assumed that these veuglaires were manufactured using tougher and harder metal as they were exposed to stronger wear in result of a higher rate of fire [9 p101-103; 24 p107; 25 p22].
In the case of the three largest Teutonic cannons the chemical composition varies. Regarding the largest ordnance, that is, the Grose Bochse, the content of tin is nearly 13% Sn, which may suggest extra toughness. The amount of tin was even higher (nearly 17.5% Sn) in the case of the Bochse nest der grosen. On the other hand, worth noting is the share of lead (0.85% Pb) in the metal of the Grose Bochse. It was added on a single occasion only, when the chase of the ordnance was cast again. As regards the Lange Bochse from 1409, its tin content (more than 5.5% Sn) is more similar to that in the smaller cannons than in the largest ordnances [9 p103; 23 p56, 58-60; 51 p32-33, Tab. 1].
Technological examinations of the cannon from Grodno
Four samples were analysed altogether – three of these (Samples 1-3) came from the loose parts of the chase found with the cannon, while Sample 4 was taken from the front edge of the chase part within the gun’s main body. The samples were mounted in Electro-Mix electroconductive resin, ground on SiC papers (500-2000 grits) and polished with diamond pastes (6, 1 and 0.5 μm). Next, they were etched with a Mi17Cu reagent (10g FeCl3, 30ml HCl, 120 ml C2H5OH) for 2 seconds in order to reveal the microstructure. Metallographic observations (for Samples 1 and 4 only) were carried out with an OptaTech MM100 inverted metallographic microscope (magnifications x50-x200; bright field) coupled with a 16 mpx digital camera. Chemical composition analyses of all samples were carried out with a JEOL JSM-6480 scanning microscope operating at 20 kV and equipped with an EDS-type detector. The equipment was energy calibrated using an Al-Cu standard reference sample. The measurement time was 50 s per point and quantitative analyses were done using the non-pattern method. The detection limit was 0.1wt%, and the measurement error was <10% for major elements (above 1.0wt%) and <30% for minor elements (below 1.0wt%). Results are averages of several measurements over the whole surface of each sample (see Table 1). While discussing the results of the technological analyses it must be remembered that the artefact was found in a fire-related archaeological layer. Thus, a prolonged exposure to heat may have influenced the cannon’s microstructure.