George Plantagenet, 1st Duke of Clarence not present – Edward himself prosecuted his brother, and demanded that Parliament pass a Bill of Attainder against his brother, declaring that he was guilty of "unnatural, loathly treasons" which were aggravated by the fact that Clarence was his brother, who, if anyone did, owed him loyalty and love. Following his conviction, he was "privately executed" at the Tower on 18 February 1478, by tradition in the Bowyer Tower, and soon after the event, the rumour gained ground that he had been drowned in a butt of Malmsey wine. Richard III biographer Paul Murray Kendall believes that the reason that
The True Tragedy of Richard III a source for his play, though the majority tend to favour this judgement. Geoffrey Bullough treats "The True Tragedy" as a "probable source" for "Richard III", citing several commonalities (as when, in both plays, Richard calls for a horse on Bosworth Field, yet refuses to flee the battle) — though Bullough admits that the nature of the plays' relationship is "not clear." The uncertainty in dating has allowed a few commentators to propose a reversed priority, and to argue that the author (or reviser) of "The True Tragedy" may have borrowed from Shakespeare's play. Shakespeare appears to have known of