Very interesting episode in the life of Henry II involved his relationship with Archbishop Thomas Becket. Henry appointed his friend because he thought he could control him, but Becket turned out to be his own man.
After one altercation on Christmas Day 1170 Henry uttered the words "Will no one rid me of this turbulent priest?" Four of his knights failed to recognise this as a rhetorical question and went off and murdered Becket in Canterbury Cathedral.
Henry spent most of his life doing penance for this crime. To pick up a coin that nobody has touched since those times is a real buzz.