"the prince of turncoats"
Wenlock was a Lancastrian up to the Battle of Ludford Bridge in 1459 after which he left England as an adherent of the Yorkist Edward Earl of March. Following Edwards marriage to Elizabeth Woodville he followed Richard Neville's lead, eventually changing his allegiances to Lancaster when Henry VI was returned to the throne in late 1470.
He was killed at Tewksbury some five months later.
Historians have a difference of opinion over Wenlock, debating whether he deserved to be remembered as a turn coat. Personally, I think he did, his dithering at Tewksbury not only cost him his life, but the lives of many of the Lancastrian army. Wenlock's inactivity on the battlefield was the focal point for Gloucester's men who used this opportunity to make their attack, but it greatly angered Edmund Beaufort, Duke of Somerset.
Wenlock was an experienced soldier, so was his hesitation due to the fact he was considering changing sides again? We will never know. Somerset is said to have accused him of treason and killed him there and then.