John of Gaunt III's rule was becoming unpopular due to high taxation and his affair with Alice Perrers, political opinion closely associated the Duke of Lancaster with the failing government of the 1370s. Furthermore, while King Edward and the Prince of Wales were popular heroes due to their successes on the battlefield, John of Gaunt had not won equivalent military renown that could have bolstered his reputation. Although he fought in the Battle of Nájera (1367), for example, his later military projects proved unsuccessful. When Edward III died in 1377 and John's ten-year-old nephew succeeded as Richard II of England, John's influence strengthened.
John of Gaunt Portugal and had concentrated his forces on the Portuguese border. He was wrong-footed by John's decision to invade Galicia, the most distant and disaffected of Castile's kingdoms. From August to October, John of Gaunt set up a rudimentary court and chancery at Ourense and received the submission of the Galician nobility and most of the towns of Galicia, though they made their homage to him conditional on his being recognised as king by the rest of Castile. While John of Gaunt had gambled on an early decisive battle, the Castilians were in no hurry to join battle, and he began