Two palaeogeographic concepts exist for the Silurian development of the Teplá-Barrandian Unit (TBU, Bohemian Massif): (1) It may represent an isolated peri-Gondwanan microplate called Perunica [1], whose palaeolatitudes changed from ca. 40o S to 25o S over the time period from 440 Ma to 420 Ma [2] or (2) there was no such an independent terrane, the TBU was never widely separated from the adjacent Saxothuringian and Moldanubian units, and remained at palaeolatitudes 45o S till 420 Ma [3]. Current research integrates chemistry of synsedimentary basaltic volcanism and palaeomagnetic data from Silurian volcano-sedimentary complexes of the Prague Basin with relevant palaeobiogeographic models to solve this long-standing controversy.