The Byzantine Empire (or Byzantium) was the Roman Empire during Late Antiquity and the Middle Ages, centered on the capital of Constantinople. The Byzantine army was a direct descendant of the Roman army. It was among the most effective armies of western Eurasia for much of the Middle Ages. The cavalry became more prominent as the legion system disappeared in the early 7th century. The Byzantine-Bulgarian Wars were a series of conflicts fought between the Byzantines and Bulgarians between the 5th and 14th centuries. Light cavalry were primarily used for scouting, skirmishing and screening against enemy scouts and skirmishers. They were also useful for chasing enemy light cavalry, who were too fast for the Catphracts. Light cavalry were more specialized than the Cataphracts, being either archers and horse slingers or lancers and mounted javelineers.