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 on 24 August 1369 at the age of 17 to the 14-year-old Philippa, the only child of the late Lionel of Antwerp, Duke of Clarence, the second son of Edward III.

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.

[2] On the accession of Richard II, a minor, in 1377, the Earl became a member of the standing council of government; though as the husband of the heir-presumptive to the crown he wisely refrained from claiming any actual administrative office.

The richest and most powerful person in the realm was, however, the king's uncle John of Gaunt, whose jealousy led March to accept the office of Lord Lieutenant of Ireland in 1379.