He was the son of Robert de Vere, 19th Earl of Oxford and his wife Beatrix van Hemmend. He was educated at Friesland in the Netherlands after his father was mortally wounded at the Capture of Maastricht in 1632, when de Vere was only six years old; years later he joined the English Regiment of Foot serving on the continent with the Dutch. He remained in Holland during the period of the English Civil War, but returned to England in 1651 an ardent royalist. He was involved in a succession of plots, for which he was imprisoned in the Tower of London for allegedly plotting against Oliver Cromwell and interned without trial. On release he joined Sir George Booth's rising in 1659 against Richard Cromwell's regime. He went with five other peers to petition The Hague for the return of King Charles II in early May 1660. Hoping but failing to become Lord Chamberlain, he was offered the Colonelcy of the Royal Horse Guards. As a favourite of royal mistressBarbara Villiers, Duchess of Cleveland he courted the Earl of Bristol's daughter, whose family were in favour at court. The daughter married Robert Spencer, 2nd Earl of Sunderland, a Secretary of State, but he lobbied the King on Oxford's behalf. Oxford was made Lord Lieutenant of Essex and a Knight of the Garter. Censorious Whigs like Samuel Pepys deplored seeing Oxford wearing his Garter regalia in public and there was a rumour that he married an actress in secret. The actress was Hester Davenport and the wedding supposedly took place on a Sunday morning in 1662 or 1663 in a chandler's shop on Harts Horn Lane, London. She had a son Audrey from this union. The earl brought a lawsuit in 1686 to refute her claims, a lawsuit he won. Despite being a Cavalier, he adhered to Protestant principles, permitting Quakers and Puritans to join the regiment. He was a friend of Charles II's illegitimate son, the Duke of Monmouth. Oxford raised a regiment of horse from 1684 onwards, just as the Life Guards were being withdrawn from Dunkirk. They were properly the Royal Regiment of Horse, but known by the colour of the uniforms as Oxford's Blues because he was the regiment's Colonel. Royalist volunteers added strength to this Protestant regiment. It was Charles II's policy to expand the army beyond the kernel that he inherited. Oxford gained the disapproval at court of the Duke of Buckingham, who had declared undying enmity. Oxford replied that he "neither cared for his friendship nor feared for his hatred." "...a troop of horse, excellently mounted, of the Royal Regiment of my Lord Aubrey de Vere, Earl of Oxford...inspecting every file of the company, the officers of which wore a red sash with gold tassels.", wrote Prince Cosmo of Tuscany on a visit to London in 1668. Oxford was present at the first Army Board on 5 August 1670, chaired by the Duke of York, the king's brother who later succeeded him as King James II. On 5 July 1685 Sir Francis Compton was promoted to command the regiment. Oxford wanted the post for himself but was prevented from taking it by the King. Oxford was responsible for kitting out his regiment, and ordered a standard blue uniform from a woollen draper, Mr Munnocks of The Strand, Middlesex, whose son was killed in the service. Oxford as Lord Lieutenant of Essex was responsible for raising troops in the county, but refused James II's order to appoint Roman Catholics to public offices. In February 1688 he told King James "I will stand by Your Majesty against all enemies to the last drop of my blood. But this is a matter of conscience and I cannot comply." He was deprived of his offices. Months later he took the side of William of Orange against James II in the Glorious Revolution. He was restored to his titles and the colonelcy of The Blues, and exempted the Commission of Inspection by the Convention Parliament of April 1689. The Secretary at War, William Blathwayt, wrote asking for details of all officers removed by absolutism. On 1 February 1689 Oxford and Compton lobbied Parliament to pass a vote of thanks to the army for the Whig constitution "...testified their sturdy adherence to the Protestant religion and being instrumental in delivering this country from popery and slavery." He died in 1703 without surviving male issue, making the title extinct. His daughter Lady Diana de Vere married Charles Beauclerk, Duke of St Albans, another illegitimate son of Charles II.
Family
On 12 April 1647 he married Anne Bayning, a daughter of Paul Bayning, 2nd Viscount Bayning. Anne died in 1659. On 12 April 1673 Aubrey married his mistress Diana Kirke, daughter of George Kirke and granddaughter of Aurelian Townshend. They had five children:
Since he had no surviving sons and as no other suitable claimant came forward, he became the last de Vere Earl of Oxford, one of the longest-lived titles in the peerage of England; the first de Vere earl had received his title from the Empress Matilda in 1141. His descendants through Diana Beauclerk were named De Vere Beauclerk, and their son Vere Beauclerk received the barony of Vere in 1750.
