2i8 A Short History of The World a couple of hundred miles of the Adriatic Sea in the region of what is now Bosnia and Serbia. It makes a square re-entrant angle there. The Romans never kept their sea communications in good order, and this two hundred mile strip of land was their line of communica- tion between the western Latin-speaking part of the empire and the eastern Greek-speaking portion. Against this square angle of the Danube the barbarian pressure was greatest. When they broke through there it was inevitable that the empire should fall into two parts. A more vigorous empire might have thrust forward and recon- quered Dacia, but the Roman empire lacked any such vigour. Con- stantine the Great was certainly a monarch of great devotion and intelligence. He beat back a raid of the Goths from just these vital Balkan regions, but he had no force to carry the frontier across the Danube. He was too pre-occupied with the internal weaknesses of the empire. He brought the solidarity and moral force of Chris- tianity to revive the spirit of the declining Empire, and he decided to create a new permanent capital at Byzantium upon the Hellespont. This new-made Byzantium, which was re-christened Constantinople in his honour, was still building when he died. Towards the end of his reign occurred a remarkable transaction. The Vandals, being pressed by the Goths, asked to be received into the Roman Empire. They were assigned lands in Pannonia, which is now that part of
