BRISTOL, ENGLAND—New research announced by the University of Bristol has shown that Anglo-Saxons used birch bark tar, a technology previously believed to be limited to prehistoric populations. The sticky, water-resistant adhesive was used beginning in the Paleolithic period throughout Europe as a sealant and for its medical properties, but it was generally thought that birch bark tar was replaced by pine tar by the Roman period. Now a team of archaeologists has identified a lump of birch bark tar in an Anglo-Saxon child's grave dating to A.D. 440–530, and birch bark tar coating the inside of a ceramic jar from a cemetery dating to perhaps a hundred years later. The researchers suspect that in both cases the tar was being used as a medicine. To read in depth about the early Anglo-Saxon period in Britain, go to "The Kings of Kent."