This paper deals with the so-called transitional phase B2/C1, the nature of which is still being debated in the archaeological literature. The heart of the discussion is in its archaeological relevance, the dating, and its cultural, ethnic and social background. THe general consensus is that it dates to the time of Marcomannic wars. On the basis of new archaeological evidence and an analysis of some diagnostic forms found on the datable sites north of the Danube, it is suggested that the Late Roman phase C1a overlaps to a large extent with the so-called transitional B2/C1 phase, which began shortly before AD 180. A question arises of how to define the subsequent phase C1a and whether both phases in question can be seen as separate stages with separate chronological sequences. Controversy surround the proposed detailed division of the transitional phase between Early and Late Roman Period into two phases and therewith also a sharp chronological diffrentiation of the archaeological material from the late 2nd century and approximatively the first third of the 3rd century. The emergence of a specific archaeological milieu relatin to the transitional phase probably has an ethnic and socio-cultiral background. It shows strong infuences from the Roman provinces. Its characteristic features may be considered as a reflection of wars and their aftermath., Jaroslav Tejral., and Obsahuje seznam literatury