The Japanese warrior or Bushi specified the professional warrior as distinguished from peasant conscripts, court military officials, and palace guards. One of the Taira leaders, Masakado involved himself in disputes centered on the resistance of landowners to provincial exactions. The Masakado rebellion marked the advent of the private professional warrior in Japanese political history. Another revolt was that of Tadatsune who seems to have become involved in the plunder of government tax receipts in two provinces, Kazusa and Shimōsa, where he was a vice governor at one time. Two lengthy wars followed the Tadatsune revolt at twenty-year intervals, keeping the east, in this case the far northeast end of Honshu beyond the Kanto provinces, in a state of unrest for nearly 60 years. The two later eleventh-century wars are called the Earlier Nine Years' War (zen kunen no eki: 1051-62, or 1056-62 according to some) and the Later Three Years' War (go sannen no eki: 1083-87).