Background
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.
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. 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.
Constance died at Leicester Castle and was buried at the Church of the Annunciation, Newark, Leicester.
