Introduction

Catherine of Lancaster (1373–1418) was the only child of Castilian princess Constanza (1354‒1394). Her mother was the eldest daughter of the king of CastileCastileKing of, Pedro I (1334–1369). Pedro had been given the name ‘the Cruel’ by the TrastámaraTrastámara (lineage of the Kings of Castile from Enrique II) victors in the Castilian civil warWarCivil war after he was murdered by his illegitimateIllegitimate sibling, Enrique II (1333–1379), the Count of TrastámaraTrastámara (lineage of the Kings of Castile from Enrique II)Count of. Following the victory of Enrique II, many of the exiled followers of Pedro, the petristas(followers of Pedro I of Castile), followed Constanza and her husband, John of Gaunt (1340–1399), back to England, where they took up residence at the Gaunt palace on the Strand.