An archaeological excavation conducted on U Kasáren St. in the Prague Castle area (Czech Republic) in 2020 revealed the remains of a medieval settlement consisting of houses of different constructions (pit dwelling, masonry construction), pyrotechnical (possibly metallurgical) features and unspecified pits. The excavation also revealed evidence of fire events and traces of viniculture on the outskirts of the Prague Castle area. Archaeological data allowed only a rough dating of the investigated settlement in the 10th–13th centuries. This paper presents the results of the radiocarbon dating of various materials (animal bones, archaeobotanical samples) from the settlement features and the contribution of the results to the clarification of the chronology of the site.

Rýzmburk Castle is one of the largest and most important medieval castles in Bohemia, documented since 1250 AD. Its North tower is assumed to be built in 1260–1300 AD. To test this assumption, the surface layers of mortar were inspected for the presence of charcoals suitable for radiocarbon dating, and 10 charcoals were found. The charcoals probably originated from wood used for lime burning. The results of radiocarbon dating using accelerator mass spectrometry agree with the historical estimation. Single post-1287 sample indicates that the building date might be refined to 1287–1300 AD.

An international consortium of radiocarbon (14C) laboratories was established to date the origin of the St. George’s Rotunda in Nitrianska Blatnica (Slovakia), because its age was not well established in previous investigations. Altogether, 20 samples of wood, charcoal, mortar and plaster were analyzed. The 14C results obtained from the different laboratories as well as between the different sample types were in good agreement, resulting in a 14C calibrated age of 783–880 AD (94.2% probability) for the Rotunda. Although the 14C results have very good precision, the specific plateau-shape of the calibration curve in this period caused the wide range of the calibrated age. The probability distribution from OxCal calibration shows, however, that about 86% of the probability distribution lies in the period before 863 AD, implying that the Rotunda could have been constructed before the arrival of Constantine (St. Cyril) and St. Methodius to Great Moravia. The Rotunda thus probably represents the oldest standing purpose-built Christian church in the eastern part of Central Europe.

The article reports on a new sampling method and the archaeological context of cave drawings, which include the oldest currently known graffiti in the Czech Republic. Between 2016 and 2020, samples with a small amount of charcoal were taken from drawings found in Kateřinská Cave (Catherine’s Cave) of the Moravian Karst in the Czech Republic. A new gentle method of sampling charcoal from the cave walls was developed for the purpose of radiocarbon (14C) dating cave drawings of unknown age, while preserving the contours of the drawings. 14C analysis has provided data from four periods of prehistory and history: from the Neolithic around 5000 BC, the turn of the Neolithic and Eneolithic around 4300 BC, the Hallstatt Period from 800–450 BC, and also from the Middle Ages (13th century). The radiocarbon dates of the graffiti correspond to the dates of the pottery finds from the entrance portal of Kateřinská Cave, thus validating the dates and the sampling method.

Given the nature of medieval artifacts and resulting research requirements, a precise temporal classification is essential. It is especially important for the purposes of medieval archaeology in interpreting archaeological finds/finding situations and identifying them with a historical events or figures, for example, to identify skeletal remains of a known historical figure or to establish a chronological sequence of various cultural and architectural changes within an area. Due to the fact that the uncertainties of radiocarbon (14C) analyses have been decreasing in recent years, the applicability of 14C dating for such purposes is now growing. In this work, we aim to demonstrate the current possibilities of the use of AMS 14C analyses on specific cases and confront the results with other available data. 14C data from skeletal remains of members of the oldest Czech ruling dynasty of the Přemyslids (about 880–1306 AD) were obtained in recent years. Archaeological research conducted in the three oldest churches in the Prague Castle discovered skeletal remains of three members of the second, two members of the fourth and two members of the fifth generation. This case study of the application of 14C data has three parts: i) identification of excavated individuals; ii) demonstration of the application using current AMS-based analysis of 14C on medieval osteological material and tests of our preparation method; iii) contributing to discussion and consulting with other problematical 14C age alteration influenced by diet, age of bone collagen or seasonal variation of 14C activity. The obtained results and the issues arising from them clearly highlight the necessity of a multidisciplinary cooperation in this type of study.

When human remains are found, apart from helping explain the cause of death and determining the extent of any injuries, forensic pathologists are usually requested to determine the identity of the deceased and how much time has elapsed since his death. In the Czech Republic, the criminal liability for murder is set to a statute of limitations of 20 years. In our pilot study, tissue samples of human remains from two decedents were radiocarbon (14C) dated to estimate the date of death. In agreement with published literature, we have confirmed relatively short carbon turnover time in hair, nail, and bone fat. Therefore these samples are the most appropriate for determining date of death. Other samples, such as teeth (collagen and carbonate form) and collagen isolated from bone samples, which exhibit relatively long carbon turnover time, can be used to reduce ambiguity of dating results and to indicate some interfering influences. Given the possibility of processing multiple sample types, we also propose brief guidelines for comparing and interpreting the results of individual analyses.