We have already mentioned the fact that in the last fifteen years of his reign William had little or no trouble with his English subjects. But his life was far from being an easy one; he had both foreign enemies to meet and a turbulent baronage to keep down. Many of the new earls and barons were not born subjects of William, but Flemings, French, or Bretons, who looked upon him as merely the chief partner in their common enterprise of the conquest of England; even among the Normans themselves many were turbulent and disloyal. Within ten years of the Conquest, the king had to take arms against a rebellion of some of his own followers. Ralf, Earl of Norfolk, and Roger, Earl of Hereford, took counsel against him, and tried to enlist in their plot Waltheof, the last surviving English Earl. "Let one of us be king, and the two others great dukes, and so rule all England," was their suggestion to him, when they had gathered all their friends together under the pretence of Earl Ralf's marriage feast. Waltheof refused to join the rebellion, but thought himself in honour bound not to disclose the conspiracy to the king. When the two earls took arms they soon found that William was too strong for them. Ralf fled over sea; Roger was taken and imprisoned for life. Of their followers, some were blinded and some banished. But the hardest measure was dealt out to Earl Waltheof, whose only crime had been his silence. William was anxious to get rid of the last great English territorial magnate; he tried Waltheof for treason before the Great Council, and, when he was condemned, had him at once executed at Winchester (1076). His earldoms of Northampton and Huntingdon were, however, allowed to pass to his daughter, who married a Norman, Simon of St. Liz. [Sidenote: =Rebellion of William's son Robert.=]