Stratford served as archdeacon of Lincoln, canon of York and dean of the court of arches before 20 June 1323, when he became Bishop of Winchester, an appointment which was made during his visit to Pope John XXII at Avignon and which was very much disliked by Edward II. In 1327 the bishop joined Queen Isabella's partisans; he drew up the six articles against Edward II, and was one of those who visited the captive king at Kenilworth to urge him to abdicate in favour of his son. On 26 November 1326 he was appointed Lord Treasurer of England, a post he held until 28 January 1327.