Rudolph I. (1218-91), founder of the Imperial House of Austria, and Emperor of the Romans, was the son of Albert IV., Count of Hapsburgh. Under the king of Bohemia he served against the Prussians, and became known for valour and wisdom. He was elected Emperor of the Romans, but the king of Bohemia, refusing to accept his election, rebelled, and was defeated in battle and slain in 1278. Rudolph reigned with great success for nineteen years.