Information: - Edmund of Langley, 1st Duke of York, (5 June 1341 1 August 1402) was the fourth surviving son of King Edward III of England and Philippa of Hainault. Like many medieval English princes, Edmund gained his nickname from his birthplace: Kings Langley Palace in Hertfordshire. He was the founder of the House of York, but it was through the marriage of his younger son, Richard of Conisburgh, 3rd Earl of Cambridge, to Anne de Mortimer, great-granddaughter of Edmund's elder brother Lionel of Antwerp, 1st Duke of Clarence, that the House of York made its claim to the English throne in the Wars of the Roses. The other party in the Wars of the Roses, the incumbent House of Lancaster, was formed from descendants of Edmund's elder brother John of Gaunt, 1st Duke of Lancaster, Edward III's third son. - The House of York was a cadet branch of the English royal House of Plantagenet. Three of its members became Kings of England in the late 15th century. The House of York was descended in the male line from Edmund of Langley, 1st Duke of York, the fourth surviving son of Edward III, but also represented Edward's senior line, being cognatic descendants of Lionel, Duke of Clarence, Edward III's second surviving son. It is based on these descents that they claimed the English crown. Compared with the House of Lancaster, it had a senior claim to the throne of England according to cognatic primogeniture but junior claim according to the agnatic primogeniture. The reign of this dynasty ended with the death of Richard III of England in 1485. It became extinct in the male line with the death of Edward Plantagenet, 17th Earl of Warwick in 1499. - Richard II (6 January 1367 c. 14 February 1400), also known as Richard of Bordeaux, was King of England from 1377 until he was deposed on 30 September 1399. Richard, a son of Edward, the Black Prince, was born in Bordeaux during the reign of his grandfather, Edward III. Richard was the younger brother of Edward of Angouleme, upon whose death, Richard, at three years of age, became second in line to the throne after his father. Upon the death of Richard's father prior to the death of Edward III, Richard, by primogeniture, became the heir apparent to the throne. With Edward III's death the following year, Richard succeeded to the throne at the age of ten. - Edward of Woodstock (15 June 1330 8 June 1376), called the Black Prince, was the eldest son of King Edward III and Philippa of Hainault, and the father of King Richard II of England. He was the first Duke of Cornwall (from 1337), the Prince of Wales (from 1343) and the Prince of Aquitaine (136272). - Edmund de Mortimer , 5th Earl of March and 7th Earl of Ulster ( 6 November 1391 -- 18 January 1425 ) , was an English nobleman . A great - great - grandson of King Edward III of England , he was heir presumptive to King Richard II of England , his cousin once removed , when Richard II was deposed in favour of Henry IV. Edmund Mortimer 's claim to the crown was the basis of rebellions and plots against Henry IV and his son Henry V , and was later taken up by the House of York in the Wars of the Roses , though Mortimer himself was an important and loyal vassal of Henry V and Henry VI . Edmund Mortimer was the last Earl of March of the Mortimer family . What is the relationship between 'edmund mortimer' and 'anne de mortimer'?
The answer to this question is:
sister