In Shakespeare's Richard III, George, the Duke of Clarence, who is being held in the Tower of London tells of a nightmare he's had, "Lord, Lord! methought, what pain it was to drown!"
Shakespeare's Clarence has been imprisoned by his other brother, King Edward, because a prophecy indicated a man with a name beginning with 'G' would take the crown. Richard is quite happy with this turn of events and does nothing to help his brother. In fact, he sends two assassins to stab poor Clarence, who is then taken away to be placed it in a vat of Malmsey wine off stage.
In reality, the Duke of Clarence was guilty of plotting, and even taking up arms, against his brother and was subsequently sentenced to death. He was privately executed and, contrary to the tradition of the time, he was not beheaded.
Nobody knows for sure how Clarence was killed, but rumor quickly grew that he was drowned in a butt of Malmsey wine - his favorite tipple. A butt of wine is quite easily large enough to be drowned in, and Clarence's exhumed body is not able to give us a definitive method of death. So, it is quite possible that he was murdered with wine.
And in the interests of being fair to Richard - far from hiring his brother's killers, the real Richard vehemently opposed Edward's arresting Clarence.