Glazed ceramics are often studied from the perspective of decoration techniques, the macroscopic description of materials or the identification of pigments. Present-day research is also focused on identifying fabrication centres of workshops and how they developed; moreover, emphasis is placed on the manufacturing process or firing conditions. It is of course problematic to create an overall view or conclusion about glazed production in Central Europe because these sets are randomly examined. The study of Early Modern ceramic production in the Czech Republic, represented mainly by archaeological finds, is one of the rapidly developing topics. This study is one of the first using archaeometric data to evaluate Early Modern glazed ceramics from Prague. Archaeological finds from the waste pits of Prague’s palaces were used for this purpose.
Early Modern ceramics production in Prague shows that Bohemian pottery production fully reflected the era’s broader Central European trends in terms of shape and is comparable with assemblages of artefacts found in Germany [1-5], Austria [6-8], Switzerland [9-11], Hungary  and Poland [13, 14]. Any comparison with production from Slovakia is to some degree limited by the state of published assemblages. Generally speaking, in terms of ceramic production it can be said that during the Early Modern Age the Czech lands were part of developed Europe. The period from the 16th century to the first half of the 17th century is typified by the emergence and chiefly the increasing number of inner-glazed kitchenware and tableware. The main reason for the use of glazes in kitchenware was to prevent non-sintered ceramic bodies from absorbing water; the second reason was aesthetic. Starting in the last third of the 16th century, there was a gradual increase in pottery glazed on both sides – particularly among ceramic tableware. As in the rest of Europe, Bohemia witnessed an optimisation of ceramic forms. An individualisation of tableware is seen in the form of plates and other dishes intended for single servings. The artefact assemblages also feature numerous individual finds of ceramic items – primarily objects of a decorative character – that are not directly related to the consumption of food. A different example of the diversity of finds are technical ceramic vessels. The main aim of this work was to characterise ceramic bodies and glazes over two centuries and to find differences in the composition of both components (ceramic bodies and glazes). An important part of the study was focused on identification of the composition of glazes including colourants, their defects and corrosion products formed on the surface of glazes. Special attention was paid to investigation of technical ceramics with the aim, above all, to characterise their ceramic bodies and glazes and to ascertain whether these “chemical vessels” could be part of a single distillation apparatus (Fig. 1). An equally important part was the evaluation of historical glazes and their possible degradation. Scientific methods commonly used in archaeometry were used to meet the objectives – X-Ray analyses [15-17], optical microscopy and SEM technique in combination with X-Ray techniques [15, 18-24], thermal analyses [21-22] and Raman spectroscopy [25-27]. The main advantage of used techniques when they are used for the study of rare and precious finds is that the same samples can be investigated by a combination of these techniques.
This study is based on finds from waste pits from the Prague Castle complex and the Salm Palace in Prague’s Hradčany (Fig. 2a) district. These are predominantly finds discovered during the initial period of archaeological research in the 1920s and early 1930s. The archaeological excavations in Salm Palace were undertaken in 2009 and 2010. Finds from all waste pits cover time periods of varying length from the second half of the 15th to the first half of the 18th century. Each of these finds was subjected to a detailed analysis , on the basis of which it was dated. Concerning dating, the main emphasis was placed on the wider spatial context of the waste pits, as the dating disputableness of such findings cannot be overlooked. From historical reports we know that waste pits were often, and repeatedly, jumbled up or partially removed [29-330]. It is possible that chronologically older objects could become a part of the younger finding context. Furthermore, in general, “luxury” items have been part of living culture much longer than ordinary consumer ceramics.
Of the original set of 783 complete or substantially reconstructed objects, 40 vessels were selected for the present study based on their typological context, shape and colour of glaze. The analysed set of samples comprises pots, pipkins, jugs, bowls, cups, a mug, a distillation lid and a flowerpot. The finds studied here were evaluated as a single set with emphasis on dating the individual vessels. In order to follow technological changes in ceramics production in time, namely at the turn of the Early Modern and Modern Ages in Prague, three time groups were defined. The division of the three-hundred-year-long section into these three time groups is based on the historical development of Prague and the Czech lands. In the first time period (1450–1550), the Late Medieval traditions of ceramic production clearly disappeared. Glazed ceramics appear in the assemblages of found artefacts, but even with regard to written evidence regarding the restriction of trade with glazes, glazed ceramics were probably not a common, widespread article . The text of the fourth article of the statutes of the Potters’ Guild of Prague Old Town from 1535 states that there is a ban on “trafficking” with what were most likely scarce glaze materials without the knowledge of both of Prague’s older guilds (Old Town and New Town). Specifically, this applied to lead and iron ore. Another document providing evidence of problems with the supply of the raw materials required to produce glazes is a letter from 1551, in which the Bohemian chamber of commerce approached the governor of the Křivoklat region with a request to consider the possibility of mining lead ore near Častonice. There is a reference to potters’ clay in the seventh article of the statues from 1535, in which the Prague pottery masters call on the city councillors to intervene on their behalf with the abbot of Strahov, who is preventing them from mining clay in the vicinity of the monastery. When this is taken in combination with instructions from 1590 associated with collecting customs duties for goods brought into Old Town over the Prague Bridge, in which there is mention of “clay, when the potters’ black is being brought from the tenancy”, it is highly likely that, in the 16th century, Prague potters were using, among other things, the grey to dark grey, layers of carbonised vegetation remnants and even the coal that came with the Cenomanian clay and claystone mined in the Petřín area. In the middle of the 16th century (1550–1650), there was an increase in ceramic production in Prague and glazed ceramics started to become widely available. Vessels fired in a reducing atmosphere make up only a single-digit percentage of finds. In this period, pottery from finely levigated clay with a slightly grainy fabric was made in Prague. The thin-walled vessels were turned on a fast-rotating potter’s wheel. The ceramic assemblages are again dominated by barrel-shaped pots whose maximum width is located in the middle of the body. The majority of pots are glazed on the inside. Flat forms are represented by pans on a tripod. Another form is deep bowls. The European-wide phenomenon of this period is slip ware. This pottery was brought to Prague from nearby Beroun. The use of painted decoration appears most frequently on shallow bowls and jugs of all sizes. From the perspective of the pottery assortment, it can be stated that there was an expansion in the formal spectrum of production. These are mainly shallow bowls with a flanged rim; plates and cups newly appear. Undoubtedly, new Prague inhabitants coming from Italy, Spain and Germany participated in the development of crafts. In the second half of the 16th century, these national minorities formed a significant and relatively large population of Prague . The beginning of the third period (1650–1750) is marked by the end of the Thirty Years’ War (1648). In the second half of the 17th century there were significant changes in the power organization of Europe. These changes were then reflected in all areas of life.
So the oldest group of findings is dated to the second half of the 15th and the first half of the 16th century. The second time group is defined by the second half of the 16th century to the first half of the 17th century. The youngest group of findings then comes from the second half of the 17th to the first half of the 18th century.
In addition to the usual kitchenware and tableware, three vessels which can be described as technical ceramics were analysed – a distillation lid (no. 2, Fig. 1), a jar (no. 7, Fig. 1) and a rectification bowl (no. 3, Fig. 1). In the case of technical ceramics, glazing helped to increase the resistance of the surface (the rectification lid and the bowl were glazed on the inside only, while the jar was glazed on both sides). Ceramic vessels that may have formed a part of chemical equipment are rarely found in archaeological collections [2, 38-42]. Most often they come in the form of shards and only rarely can researchers analyse entire vessels. The above-mentioned findings of technical ceramics were discovered in Waste Pit B near the Old Provost House, the oldest residential building at Prague Castle located in the central part of the castle complex, adjoining St. Vitus Cathedral on the south-west. Historians identify the Old Provost House with the so-called Episcopal Court which was first mentioned in archival documents as early as the 11th century. The list of capitular houses from 1486  states that the house was divided into two parts during this period, with the archbishop using the western part and the provost inhabiting the eastern part. The building was not reunified until 1660 .
During the rescue archaeological research in July 1925, archaeologists explored Waste Pit B, which contained a rich collection of finds (ceramics, glass, iron) dating back to between 1450 and 1550 . The assemblage was recorded . Of the ceramic material found in the pit, 187 vessels were reconstructed, including three technical ceramic vessels which may have formed a distillation apparatus (Figure 2b; Liber de arte distillandi). The fact that these objects were located (and most likely used) in an ecclesiastical building makes the whole assemblage particularly interesting. The vessels were reconstructed immediately after the completion of the archaeological research in the area. The method and process used for the reconstruction were thoroughly recorded. Along with keeping a detailed survey log, the researchers also recorded the laboratory examination of the vessels [47-49]. The laboratory logs contain a detailed description of the daily process of the vessels’ reconstruction and conservation, also specifying the binders used. In addition to these routine work records, the laboratory logs contain information about extraordinary events such as a doctor’s visits, a funeral, the president’s birthday  and the visit of an American archaeological expedition from Harvard University .
The set of artefacts from Waste Pit B is only one of nine assemblages from Prague Castle and Hradčany which were analysed in this study. Of 783 vessels, we focused on 40 (Table 1), which were chosen to help answer questions related to the way ceramics were produced during the Early Modern Age in Prague .