Robert was the only son of Thomas, 8th earl of Oxford. He became 9th Earl in 1371, and married Philippa, daughter of the Earl of Bedford, a son-in-law of Edward III, quickly becoming close to Richard II. Already great chamberlain of England, he was made a member of the privy council and a Knight of the Garter. While castles and lands were bestowed upon him he was constantly in the company of the young king. In 1385 Richard asked his friend to govern Ireland, and he was given extensive rights and created Marquess of Dublin. Meanwhile the discontent felt at Richard’s incompetence and extravagance was increasing, one cause being the king’s partiality for Oxford. His divorce from Philippa, and marriage to a Bohemian lady increased the ire of the nobles against him. The king, indifferent to the gathering storm, created Vere Duke of Ireland in October 1386, and gave him still more extensive powers there, and so matters reached a climax. Richard was deprived of his authority for a short time, and Oxford was ordered in vain to proceed to Ireland. He was then accused by the Duke of Gloucester. Robert sped north and gathered an army to defend his royal master and himself. At Radcot Bridge in Oxfordshire his men fled. Oxford escaped to Holland. He was found guilty of treason in absentia and condemned to death but, with another exile, the Duke of Suffolk, he lived in Paris until Anglo French treaty in June 1389, when he took refuge at Louvain. Killed by a boar whilst hunting he left no children. In 1395 the King ordered his body back to England, and he was buried in the priory at Earl’s Colne, Essex.