In 1680 his eldest brother died, and thereupon, though the title of baronet and the paternal estate of his family were to come to him after the death of his father, yet he stuck to his holy orders, continued in his functions, and upon the translation of Doctor John Lake to the see of Chichester, was nominated Bishop of Bristol by his Majesty, (King James the Second, Nov. 8, 1685,) whereupon, after he had been diplomated doctor of divinity, he was consecrated, November the 8th 1685, in the Archbishop’s Chapel at Lambeth, and introduced into the House of Lords with Dr. Ken, Bishop of Bath and Wells, on the 11th day of the same month. On the 8th of June 1688 he was one of the six Bishops, besides Doctor Sancroft the Archbishop, that were committed prisoners to the Tower of London, for the alleged offence of contriving, making, and publishing a seditious libel against his Majesty and his government; that is for subscribing a petition to his Majesty, wherein he and the rest of the said Bishops showed the great averseness that they found in themselves to the distributing and publishing in all their churches his Majesty’s late declaration for liberty of conscience, &c. Where continuing till they were publicly tried in Westminster Hall for the same, they were, to the great joy of the true sons of the Church of England, released thence on the 15th of the same month. Subsequently, however, the see of Exeter was conferred on him by King James, vacant by the translation thence to York of Doctor Lamplugh; and about the 7th of April following, his Majesty King William the Third was pleased to give his royal assent for him, the said Doctor Jonathan Trelawny, Bishop of Bristol, to be Bishop of Exeter, in the place of Doctor Lamplugh, beforementioned. From the Fasti it appears that Jonathan Trelawny, of Christ Church, was admitted Bachelor of Arts on the 14th of May 1672, and Master of Arts April the 29th, 1675. And on October the 26th, 1685, Sir Jonathan Trelawny, Bart. Master of Arts of Christ Church, the nominated Bishop of Bristol, was diplomated Doctor of Divinity. As this gentleman was made Bishop of Bristol by King James the Second, and after his commitment to the Tower and acquittal, accepted from him an appointment to the bishopric of Exeter, almost the last act of that king’s government, which appointment was almost immediately confirmed to him by King William on his joining in the Revolution, one may apply in his case the observation made by the most philosophical writer of English history, on the Duke of Marlborough, when he led over Queen Anne to the Prince of Orange. “This conduct was a singular sacrifice to public virtue of every duty in private life, and required for ever after the most upright, disinterested, and public-spirited behaviour to render it justifiable.” He was further advanced by Queen Anne, being again translated, on the 14th of January 1707, to the see of Winchester. He died on the 21st of June 1721.