Philippa, 5th Countess of Ulster

Philippa of Clarence also known as Philippa Plantagenet or Philippa de Burgh or Philippa of Eltham (16 August 1355 – ) was a medieval English princess and the suo jure Countess of Ulster.

Biography She was born at Eltham Palace in Kent on 16 August 1355, the only child of Lionel of Antwerp, 1st Duke of Clarence, and Elizabeth de Burgh, 4th Countess of Ulster. Her father was the second surviving son of King Edward III of England and Philippa of Hainault. She was the eldest grandchild of King Edward and Queen Philippa, her namesake.

Philippa married Edmund Mortimer, 3rd Earl of March, at the age of fourteen, in the Queen's Chapel at Reading Abbey. Her cousin, King Richard II, remaining childless, made Philippa and her descendants next in line to the throne until his deposition. In the Wars of the Roses, the Yorkist claim to the crown was based on descent from Edward III through Philippa, her son Roger Mortimer, and granddaughter Anne Mortimer, who married Richard of Conisburgh, 3rd Earl of Cambridge, a son of her uncle Edmund of Langley, 1st Duke of York.

Philippa died in around 1377, the same year as her grandfather Edward III. The precise date of her death is unknown, but Philippa had certainly died by December 1379. Her date of death is often confused with that of her mother-in-law, who died in January 1382. Philippa was buried at Wigmore Abbey, Herefordshire.

Marriage and issue Her children with Edmund Mortimer were as follows:

NameBirthDeathNotesLady Elizabeth Mortimer12 February 137120 April 1417She first married Sir Henry 'Hotspur' Percy, with whom she had two children, Henry Percy, 2nd Earl of Northumberland, and Lady Elizabeth Percy. Her second husband was Thomas de Camoys, Baron Camoys, with whom she had a son, Lord Roger de Camoys. Elizabeth Mortimer was an ancestor of the third queen consort of Henry VIII, Jane Seymour.Roger Mortimer, 4th Earl of March11 April 137420 July 1398He married Lady Alianore Holland, by whom he had four children, Anne, Edmund Mortimer, 5th Earl of March, Eleanor, and Roger. The House of York's claim to the throne was through his eldest daughter, Anne Mortimer.Lady Philippa MortimerShe first married John Hastings, 3rd Earl of Pembroke. Her second husband was Richard Fitzalan, 11th Earl of Arundel, with whom she had a son, John, who died young. Her third husband was Sir Thomas Poynings of Basing, 5th Baron St. John.Sir Edmund Mortimer9 November 1376before 13 May 1411Married Catrin (Catherine) Glyndŵr, the daughter of Owain Glyndŵr. They had issue, possibly a son named Lionel, said to have died young, and three daughters who died in the Tower of London alongside their mother.

Ancestry