"In no victory do they glory so much as in that which is gained by dexterity and good conduct without bloodshed."
-Sir Thomas More, from Utopia (1515)
Thomas More's utopian vision featured (among other things) an adherence to non-violence, a simple and fair legal code, and a reasonable monarch who governs with one finger placed upon the pulse of philosophy.
These visions of an ideal society did nothing to help More in 1535, when a jury convicted him of high treason (on thin evidence) and sentenced him to death. The prolific author and statesman had refused to take the Oath of Supremacy, which declared allegiance to the English monarch as head of the Church of England. He also refused to support the marriage annulment that allowed King Henry VIII to marry Anne Boleyn.
More was beheaded July 6, 1535, though not before reportedly stating, "I die the king's good servant, but God's first." He was canonized by Pope Leo XIII in 1886.
In short, the death of Thomas More can be attributed to (among other things) a blood-obsessed society, an unjust legal system, and a tyrannical king whose fingers were otherwise occupied.
"Sir Thomas More" by Hans Holbein, the Younger