1 Pottery Firing without a Kiln. Hand-Built Pottery in the Territory of the Present-Day Latvia in the Middle and Late Iron Age (5 th - 12 th centuries) Baiba Dumpe 1) , Agnese Stunda-Zujeva 2) , Jana Vecstaudža 2) 1) National History Museum of Latvia 2) Institute of General Chemical Engineering, Riga Technical University Abstract The presented research focuses on hand-built pottery produced in Latvia in the middle and late Iron Age (5 th – 12 th centuries). The colour of vessel surface and the appearance of the sherd fracture surface are among the indicators of the conditions during firing. However, these primary features may have changed both in the course of the pottery use and after the respective vessel life ended and its sherds found their way into the occupation layer. Through experiments and with the help of X-ray powder diffraction analysis (XRPD) the authors sought to establish how the pottery firing process was organised, with special focus on determining the firing temperature interval. In the course of research 40 pottery samples from archaeological settlements and burial sites were analyzed. Concurrently series of samples from several clay deposits of Latvia were taken. These samples were open-fired imitating the hypothetical pottery firing regime. This was the first time that XRPD analysis was used in the research of archaeological pottery of Latvia. The results of the analysis indicated that the samples had been fired at the maximum temperature not lower than 600°C, but not higher than 900°C. The experiments allow defining the ancient pottery firing temperature maximum interval within the range of 600-700°C. Introduction: Archaeological context Throughout the studied period vessels were made without a potter’s wheel except in the second half of the late Iron Age (the 11 th and 12 th centuries), when the production of wheel-shaped pottery began, while the production of hand-built pottery also continued. From the 12th century production of hand-built pottery gradually ended. (Stubavs 1976, Šnore 1961, and others).