Facts and Events
Constance of Castile (1354 – 24 March 1394) was claimant of the Castilian throne after the death of her father Peter the Cruel, her mother being María de Padilla, whom Peter had secretly married but was then forced to repudiate, only to keep her as a mistress. She married, at Roquefort, near Bordeaux, Guienne, on 21 September 1371, John of Gaunt, 1st Duke of Lancaster, third son of Edward III of England and Philippa of Hainault, as his second wife. Her younger sister, Infanta Isabella, married Edmund of Langley, 1st Duke of York, the fourth son of King Edward III and Queen Philippa.
On 9 February 1372 Constance made a ceremonial entry into London as Queen of Castile, accompanied by Edward, the Black Prince, and an escort of English and Castilian retainers and London dignitaries. Crowds lined the streets to see her as she processed to the Savoy Palace in the Strand where she was ceremonially received by her husband, who had proclaimed himself King of Castile and León on 29 January.
This was the way for Gaunt to obtain a kingdom of his own (he had also pursued Scotland), as his nephew Richard II and the descendants of his brother Lionel of Antwerp, 1st Duke of Clarence stood between him and the Crown of England. John of Gaunt claimed the title of King of Castile jure uxoris, and insisted that English nobles address him as "my lord of Spain", but was unsuccessful in his attempts to obtain the crown. Their daughter Catherine of Lancaster was married to the king of the Trastámara line, Henry III of Castile, thus uniting these two rival claims.
Constance died at Leicester Castle and was buried at Newark Abbey, Leicester.[This is actually a college which was known as St. Mary's of the New Work, or Newarke, to distinguish it from the older college of St. Mary de Castro inside the borough.[see-http://www.british-history.ac.uk/report.aspx?compid=66575 ]