Earl of Oxford is a dormant title in the Peerage of England, first created for Aubrey de Vere by the Empress Matilda in 1141. His family was to hold the title for more than five and a half centuries, until the death of the 20th Earl in 1703. The de Veres were also hereditary holders of the office of Master Chamberlain of England from 1133 until the death of the 18th Earl in 1625. Their primary seat was Hedingham Castle in Essex, but they held lands in southern England and the Midlands, particularly in eastern England. The actual earldom was called 'Oxenford' until at least the end of the 17th century. Medieval sources thus refer to 'my lord of Oxenford' when speaking of the earl. Earls of Oxford (1141) Soon after his father's death in 1141, Aubrey III de Vere was recruited by Empress Matilda. Aubrey's brother-in-law, Geoffrey de Mandeville first earl of Essex, apparently negotiated the offer of the earldom of Cambridge, with a secondary offer of one of four counties if Cambridgeshire was claimed by her kinsman. Aubrey held no land in Oxfordshire at the time, but his eldest son Aubrey IV was to marry an heiress with manors in that county. Aubrey IV was supposedly an ally of King John, while his brother Robert, the 3rd Earl was one of the 25 barons of Magna Carta. His descendant, another Robert, the 9th Earl, was a favourite of King Richard II who created him Duke of Ireland. John the 13th Earl was a Lancastrian during the War of the Roses and Henry Tudor's commander at the Battle of Bosworth Field in 1485. The 17th Earl has become the most famous of the line because of his emergence as a popular alternative candidate as the actual author of the works of William Shakespeare (see Oxfordian theory of Shakespeare authorship). The 17th Earl was a ward and later son-in-law of Lord Burghley, Queen Elizabeth I's Secretary of State. On the death of the 20th Earl, without identifiable heirs male, the title became dormant. The Earls of Oxford held no subsidiary titles, and so their heirs apparent were styled by invented courtesy titles: initially Lord Vere, and later Viscount Bolebec (sometimes spelt Viscount Bulbeck). The principal Oxford coat of arms or shield was quarterly gules and or (red and yellow) with an argent (white) five-pointed star called a mullet or molet