Edgar "the Peaceable"
During Edgar's reign, it was said that a woman with a baby and a sack of gold could walk from one end of England to the other with perfect confidence and safety. This is not too much of an exaggeration; England was in fact remarkably peaceful during Edgar's reign, thanks to draconian laws that involved having one's tongue ripped out, at best, for stealing an apple. The penalties took off from there.
Edgar himself, however, felt absolutely no obligation to follow these laws. He was the king, and he could do as he liked. Mostly this involved attending to his official duties and womanizing. Upon the death of his second wife, Edgar decided to marry again, and the prime candidate was the Princess Alfthryth of one of England's surviving small kingdoms. Edgar sent his trusted right-hand man, Ethelwold, to scout Alfthryth out, and, if she came up to standard, to woo and marry her by proxy.
Ethelwold wooed and married Alfthryth--but for himself, not his master. This posed him with a problem: how to explain? Ethelwold told the king that Alfthryth sadly had turned out to be countrified and rather plain, and not at all fit for His Majesty. But perfectly appropriate for him, Ethelwold. Edgar listened and then invited himself to dinner at the newlywed's home so that he could see for himself. Ethelwold promptly rushed home, explained the whole situation, and begged Alfthryth to make herself as plain as possible. This was the first Alfthryth had heard that she could have been Queen, and when Edgar came around, Alfthryth was at her most charming. Shortly afterwards Edgar and Ethelwold went into the woods to chat, but only Edgar came out; Ethelwold had been stabbed in the back. Literally.