John Hartstonge was the third son of Sir Standish Hartstronge, (a Baron of the Exchequer in Ireland) and was born on the 1st December 1654 at Catton near Norwich. Educated at Trinity College, Dublin, he graduated B.A. 1677. He continued his studies at Gonville and Caius College, Cambridge, graduating M.A. 1680 and later became a fellow. Hartstronge also spent a year at Glasgow University. In 1681 he was appointed Chaplain to the First Duke of Ormonde (then the Lord Lieutenant of Ireland) until his death in 1688. He continued in the same capacity with the Second Duke and accompanied him in his campaign in Flanders. It was under his patronage that he received his subsequent preferments. In June 1684 he became Archdeacon of Limerick and was subsequently attained by King James' Irish Parliament of 1689, under the name of Henry Hartstronge. After the Williamite victory, the King, at the instigation of Ormonde, promoted Hartsronge to the bishopric of Ossory in April 1693. In March 1714 he was translated to Derry. He died in Dublin on the 30th January 1717.