Julius Ceasar's Roman legions invaded Switzerland in 58 B.C., followed by the Germanic Alemanni, Burgundians, Ostrogoths, and ranks. During the 10th and 11th centuries, the Holy Roman Empire ruled. Peasants and workers became increasingly unhappy. In 1291 the cantons of Uri, Schwyz, and Unterwalden declared their independence of the Habsburgs. The rebellious cantons established a mutual defense alliance and were joined a few years later by Luzern, Zurich, and Bern. Austrians and Burgundians made several attempts at checking the independence movement over the next 200 years. By the early-16th century, Switzerland not only maintained its independence, but had become a military power. The present Swiss policy of neutrality was begun after defeat at the hands of the French at Marignano in 1515.