Edmund Mortimer (1351—1381), 3rd earl of March and 1st Earl of Ulster, was son of Roger Mortimer, 2nd Earl of March, by his wife Philippa, daughter of William Montacute, 1st Earl of Salisbury.

Early Life

Being an infant at the death of his father, Edmund, as a ward of the crown, was placed by Edward III of England under the care of William of Wykeham and Richard Fitzalan, 10th Earl of Arundel.

The position of the young earl, powerful on account of his possessions and hereditary influence in the Welsh marches, was rendered still more important by his marriage in 1368 at the age of 17 to the 13 year old Philippa, the only child of Lionel of Antwerp, Duke of Clarence, third son of Edward III.

Lionel's wife, Elizabeth, was daughter and heiress of William de Burgh, 6th Lord of Connaught and 3rd Earl of Ulster, and Lionel had himself been created Earl of Ulster before his marriage. Edmund inherited the title Earl of Ulster on Lionel's death.

Therefore, the Earl of March not only represented one of the chief Anglo-Norman lordships in Ireland in right of his wife Philippa, but Philippa's line was also the second most senior line of descent in the succession to the crown, after Edward, the Black Prince and his son, King Richard II of England.

This marriage had, therefore, far-reaching consequences in English history, ultimately giving rise to the claim of the House of York to the crown of England contested in the Wars of the Roses; Edward IV being descended from the third son of Edward III as great-great-grandson of Philippa, countess of March, and in the male line from Edmund of Langley, fifth son of Edward III.

Edmund's son Roger Mortimer, 4th Earl of March would become heir presumptive to the English crown during the reign of Richard II.

Political Advancement

Mortimer, now styled Earl of March and Ulster, became Marshal of England in 1369, and was employed in various diplomatic missions during the next following years. He was a member of the committee appointed by the Peers to confer with the Commons in 1373—the first instance of such a joint conference since the institution of representative parliaments—on the question of granting supplies for John of Gaunt’s war in France.

He participated in the opposition to Edward III and the court party, which grew in strength towards the end of the reign, taking the popular side and being prominent in the Good Parliament of 1376 among the lords who supported the Prince of Wales and opposed the Court Party and John of Gaunt. The Speaker of the Commons in this parliament was March’s steward, Peter de la Mare, who firmly withstood John of Gaunt in stating the grievances of the Commons, in supporting the impeachment of several high court officials, and in procuring the banishment of the king’s mistress, Alice Perrers. March was a member of the administrative council appointed by the same parliament after the death of Edward, the Black Prince to attend the king and advise him in all public affairs.

Reign of Richard II

On the accession of Richard II, a minor, in 1377, the Earl became a member of the standing council of government; though as father of the heir-presumptive to the crown he wisely abstained from claiming any actually administrative office. The most powerful person in the realm was, however, John of Gaunt, Duke of Lancaster, whose jealousy of March led to the acceptance by the latter of the Lieutenancy of Ireland in 1379. March succeeded in asserting his authority in eastern Ulster, but failed to subdue the O’Neills farther west. Proceeding to Munster to put down the turbulency of the chieftains of the south, March died at Cork on 27 December 1381. He was buried in Wigmore Abbey, of which he had been a benefactor, and where his wife Philippa was also interred.

The earl had two sons and two daughters, the elder of whom, Elizabeth, married Henry Percy "Hotspur", son of the Earl of Northumberland. His eldest son, Roger, succeeded him as 4th Earl of March and Ulster. His second son, Edmund played an important part, in conjunction with his brother-in-law Hotspur, in the fortunes of Owain Glyndwr. The other daughter was Philippa, who married Richard Fitzalan, 11th Earl of Arundel.