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
Battle of Bosworth Field bringing along his erstwhile gaoler Sir James Blount. Oxford's presence raised morale in Henry's camp and troubled Richard III. In the early stages of the Wars of the Roses, the Stanleys of Cheshire had been predominantly Lancastrians. Sir William Stanley, however, was a staunch Yorkist supporter, fighting in the Battle of Blore Heath in 1459 and helping Hastings to put down uprisings against Edward IV in 1471. When Richard took the crown, Sir William showed no inclination to turn against the new king, refraining from joining Buckingham's rebellion, for which he was amply rewarded. Sir William's elder brother, Thomas Stanley,