Infanta Isabella of Castile, Duchess of York (c. 1355 – 23 December 1392) was a daughter of
King Peter of Castile and María de Padilla

María de Padilla

María Díaz de Padilla was the mistress of King Peter of Castile whom he married in secret in 1353.She was a Castilian noblewoman...

. She was a younger sister of Constance, Duchess of Lancaster.

In 1372, sometime between the 1 March and 30 April, Isabella married Edmund of Langley, 1st Duke of York

Edmund of Langley, 1st Duke of York

Edmund of Langley, 1st Duke of York, 1st Earl of Cambridge, KG was a younger son of King Edward III of England and Philippa of Hainault, the fourth of the five sons who lived to adulthood, of this Royal couple. Like so many medieval princes, Edmund gained his identifying nickname from his...

, fourth son of Edward III of England

Edward III of England

Edward III was King of England from 1327 until his death and is noted for his military success. Restoring royal authority after the disastrous reign of his father, Edward II, Edward III went on to transform the Kingdom of England into one of the most formidable military powers in Europe...

 and Philippa of Hainault

Philippa of Hainault

Philippa of Hainault, or, Philippe de Hainaut was the Queen consort of King Edward III of England. Edward, Duke of Guyenne, her future husband, promised in 1326 to marry her within the following two years...

 at Wallingford. As a result of her marriage, she became the first of a total of eleven women who became (as a courtesy by marriage to their husbands) Duchess of York

Duchess of York

Duchess of York is the principal courtesy title held by the wife of the Duke of York. The title is gained with marriage alone and is forfeited upon divorce. Four of the twelve Dukes of York did not marry or had already assumed the throne prior to marriage, therefore there have only ever been eleven...

. They had three children:

• Edward of Norwich, 2nd Duke of York
  Edward of Norwich, 2nd Duke of York
  Sir Edward of Norwich, 2nd Duke of York, 2nd Earl of Cambridge, Earl of Rutland, Earl of Cork, Duke of Aumale KG was a member of the English royal family who died at the Battle of Agincourt....
  
   (1373 – 25 October 1415).
• Constance of York
  Constance of York
  Constance of York, Countess of Gloucester was the only daughter of Edmund of Langley, 1st Duke of York and his wife Isabella of Castile, daughter of Pedro of Castile and Maria de Padilla. On about 7 November 1379, Constance married Thomas le Despenser, 1st Earl of Gloucester , who was eventually...
  
   (1374 – 29 November 1416). Married Thomas le Despenser and was mother of Isabel le Despenser, Countess of Worcester and Warwick
  Isabel le Despenser, Countess of Worcester and Warwick
  Isabel le Despenser, Countess of Worcester and Warwick was the posthumous daughter and eventually the sole heiress of Thomas le Despenser and his wife, Constance of York...
  
  .
• Richard of Conisburgh, 3rd Earl of Cambridge
  Richard of Conisburgh, 3rd Earl of Cambridge
  Richard of Conisburgh, 3rd Earl of Cambridge was the younger son of Edmund of Langley, 1st Duke of York and Isabella of Castile....
  
   (1375 – 5 August 1415).

She was named a Lady Companion of the Order of the Garter

Order of the Garter

The Most Noble Order of the Garter, founded in 1348, is the highest order of chivalry, or knighthood, existing in England. The order is dedicated to the image and arms of St...

 in 1378. Isabella died 23 December 1392 and on 14 January 1393 was buried in Kings Langley

Kings Langley

Kings Langley is a historic English village and civil parish northwest of central London on the southern edge of the Chiltern Hills and now part of the London commuter belt. The major western portion lies in the borough of Dacorum and the east is in the Three Rivers district, both in the county of...

 Manor House in Hertfordshire

Hertfordshire

Hertfordshire is a ceremonial and non-metropolitan county in the East region of England. The county town is Hertford.The county is one of the Home Counties and lies inland, bordered by Greater London , Buckinghamshire , Bedfordshire , Cambridgeshire and...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.

Ancestry