He was the son of Robert Charlton (and elder brother to Alan, and Thomas, Bishop of Hereford[1]) of Apley castle near Wrockwardine.

Strengthening the English authority over his Welsh lands, in 1310 he and Hawise's uncle Griffin de la Pole raised 400 footsoldiers from the lordship of Powis to fight against the Scots.

John Charlton's authority in Powys grew too much for Hawise's uncle Griffin, who was aided in his opposition by the Le Strange lords of Knockin, Shropshire.

Arundel remained loyal to the king, which gave Charlton the opportunity to rid himself of his rival by arresting and executing him (at Shrewsbury[8] or, possibly, Hereford) under the orders of the Queen.

A fourteenth-century stained glass Jesse window, now in St Mary's church, Shrewsbury, but originally in the Greyfriars, shows at the bottom right-hand corner, a knight bearing the arms of Powys who is probably Charlton.