Biography of Isabella of Castile Duchess York 1355-1392

In 1355 Isabella of Castile Duchess York was born illegitimately to [her father] Peter "Cruel" I King Castile [aged 20] and [her mother] Maria Padilla [aged 21].

On 29th May 1358 [her uncle] Fadrique Alfonso Ivrea [aged 24] was murdered at Seville on behalf of his brother [her father] Peter "Cruel" I King Castile [aged 23].

In July 1361 [her mother] Maria Padilla [aged 27] died at Seville.

On 21st September 1371 [her brother-in-law] John of Gaunt 1st Duke Lancaster [aged 31] and [her illegitimate sister] Constance of Castile Duchess of Lancaster [aged 17] were married at Roquefort, Landes. She by marriage Duchess Lancaster. His younger brother Edmund of Langley 1st Duke of York [aged 30] married Constance's sister in July 1372. An example of Marriage of Two Sets of Siblings. She the illegitmate daughter of [her father] Peter "Cruel" I King Castile and [her mother] Maria Padilla. He the son of King Edward III of England [aged 58] and Philippa of Hainaut Queen Consort England. They were half third cousin twice removed.

After 21st September 1371 Isabella of Castile Duchess York [aged 16] accompanied her sister [her illegitimate sister] Constance of Castile Duchess of Lancaster [aged 17] to England after her marriage to [her brother-in-law] John of Gaunt 1st Duke Lancaster [aged 31].

On 11th July 1372 Edmund of Langley 1st Duke of York [aged 31] and Isabella of Castile Duchess York [aged 17] were married at Wallingford, Oxfordshire [Map]. She by marriage Countess Cambridge. She being the younger sister of Constance [aged 18] who had married Edmund's older brother John of Gaunt 1st Duke Lancaster [aged 32] a year before. An example of Marriage of Two Sets of Siblings. She the illegitmate daughter of Peter "Cruel" I King Castile and Maria Padilla. He the son of King Edward III of England [aged 59] and Philippa of Hainaut Queen Consort England. They were half third cousin twice removed.

Around 1373 [her son] Edward 2nd Duke of York 1st Duke Albemarle was born to Edmund of Langley 1st Duke of York [aged 31] and Isabella of Castile Duchess York [aged 18] at King's Langley, Hertfordshire [Map]. He a grandson of King Edward III of England. He married (1) 1381 his second cousin once removed Beatrice Burgundy Countess Rutland and Cork, daughter of Ferdinand I King Portugal and Leonor Teles Meneses Queen Consort Portugal (2) before 7th October 1398 Philippa Mohun Duchess York, daughter of John Mohun 2nd Baron Mohun of Dunster and Joan Burghesh Baroness Dunster.

Around 1374 [her daughter] Constance York Countess Gloucester was born to Edmund of Langley 1st Duke of York [aged 32] and Isabella of Castile Duchess York [aged 19] at Conisbrough Castle [Map]. She a granddaughter of King Edward III of England. She married before 7th November 1379 her third cousin once removed Thomas Despencer 1st Earl Gloucester, son of Edward Despencer 1st Baron Despencer, Baron Burghesh and Elizabeth Burghesh 3rd Baron Burghesh, and had issue.

Before 7th November 1379 [her son-in-law] Thomas Despencer 1st Earl Gloucester [aged 6] and Constance York Countess Gloucester [aged 5] were married. She the daughter of Edmund of Langley 1st Duke of York [aged 38] and Isabella of Castile Duchess York [aged 24]. They were third cousin once removed. He a great x 3 grandson of King Edward I of England. She a granddaughter of King Edward III of England.

In 1381 Edward 2nd Duke of York 1st Duke Albemarle [aged 8] and Beatrice Burgundy Countess Rutland and Cork [aged 8] were married. She the daughter of Ferdinand I King Portugal [aged 35] and Leonor Teles Meneses Queen Consort Portugal. He the son of Edmund of Langley 1st Duke of York [aged 39] and Isabella of Castile Duchess York [aged 26]. They were second cousin once removed. He a grandson of King Edward III of England.

Before 1385 John Holland 1st Duke Exeter [aged 32] was rumoured to be having an affair with Isabella of Castile Duchess York [aged 29] wife of Edmund of Langley 1st Duke of York [aged 43].

On 20th July 1385 [her son] Richard of Conisbrough 1st Earl Cambridge was born to Edmund of Langley 1st Duke of York [aged 44] and Isabella of Castile Duchess York [aged 30] at Conisbrough Castle [Map]. Some historians suggest the father was John Holland 1st Duke Exeter [aged 33] with whom Isabella of Castile Duchess York was suspected of having an affair since 1. Richard received no lands from his father and was not mentioned either in his father's will nor his brother's will, 2. the age gap, around ten years, between Richard and his older siblings. He a grandson of King Edward III of England. He married (1) May 1406 his first cousin twice removed Anne Mortimer, daughter of Roger Mortimer 4th Earl March 3rd Earl of Ulster and Eleanor Holland Countess March and Ulster, and had issue (2) after 21st September 1411 his third cousin twice removed Maud Clifford Countess Cambridge, daughter of Thomas Clifford 6th Baron Clifford and Elizabeth Ros Baroness Clifford.

On 13th January 1393 Isabella of Castile Duchess York was buried at King's Langley Priory, Hertfordshire [Map].