Edmund Mortimer, son of the 3rd Earl

Sir Edmund Mortimer
Ludlow Castle, birthplace of Edmund Mortimer
Spouse(s)	Catrin ferch Owain Glyndŵr
Noble family	Mortimer
Father	Edmund Mortimer, 3rd Earl of March
Mother	Philippa Plantagenet
Born	10 December 1376 Ludlow Castle, Shropshire
Died	1409

Sir Edmund Mortimer (10 December 1376 – 1409), was an English nobleman who played a part in the rebellions of the Welsh leader, Owain Glyndŵr and the Percys at the beginning of the 15th century. He perished at the siege of Harlech as part of these conflicts. He was related to many members of the English royal family through his mother, Philippa Plantagenet, the daughter of Lionel of Antwerp, 1st Duke of Clarence, and a granddaughter of King Edward III of England.

Edmund was born on 10 December 1376 at Ludlow Castle in Shropshire as the second son of Edmund Mortimer, 3rd Earl of March, by his wife Philippa Plantagenet. He was a grandson of Lionel of Antwerp, thus a great-grandson of King Edward III. He had an elder brother, Roger Mortimer, 4th Earl of March, and two sisters, Elizabeth, who married Henry 'Hotspur' Percy, and Philippa, who married firstly John Hastings, 3rd Earl of Pembroke, secondly Richard Fitzalan, 11th Earl of Arundel, and thirdly, Sir Thomas Poynings.

Edmund was financially well provided for, both by his father, who died when Edmund was 5 years old, and by his elder brother Roger.

Edmund was a supporter of his cousin, Henry Bolingbroke, later King Henry IV, in spite of the fact that his older brother Roger had a stronger genealogical claim to the throne by reason of the fact that he and his brother were grandsons of Lionel of Antwerp, King Edward III's second surviving son, whereas Bolingbroke's father, John of Gaunt, was King Edward III's third surviving son.