From Wikipedia, the free encyclope
William de Bohun, 1st Earl of Northampton, KG (c. 1312 – 16 September 1360) was an English nobleman and military commander.
He was the fifth son of Humphrey de Bohun, 4th Earl of Hereford and Elizabeth of Rhuddlan. He had a twin brother, Edward. His maternal grandparents were Edward I of England and his first Queen consort Eleanor of Castile.

From Wikipedia, the free encyclopedia
Elizabeth de Badlesmere, Countess of Northampton (1313 – 8 June 1356) was the wife of two English noblemen, Sir Edmund Mortimer and William de Bohun, 1st Earl of Northampton. She was a co-heiress of her brother Giles de Badlesmere, 2nd Baron Badlesmere.
Elizabeth was born at Castle Badlesmere, Kent, England in 1313 to Bartholomew de Badlesmere, 1st Baron Badlesmere and Margaret de Clare. She was the third of four daughters. She had one younger brother, Giles de Badlesmere, 2nd Baron Badlesmere, who married Elizabeth Montagu, but did not have any children.
Her paternal grandparents were Guncelin de Badlesmere and Joan FitzBernard, and her maternal grandparents were Thomas de Clare, Lord of Thomond and Juliana FitzGerald of Offaly.
Elizabeth's father was hanged, drawn and quartered on 14 April 1322 for having participated in the Earl of Lancaster's rebellion against King Edward II of England; and her mother imprisoned in the Tower of London until 3 November 1322. She had been arrested the previous October for ordering an assault upon Queen consort Isabella after refusing her admittance to Leeds Castle, where Baron Badlesmere held the post of governor.[1] Elizabeth and her siblings were also sent to the Tower along with their mother.[2] She was eight years old at the time and had been married for five years to her first husband; although the marriage had not yet been consummated due to her young age.