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 dexter side of the shield (the left hand side as viewed), and the differenced English royal arms on the sinister; but in 1388, when he surrendered his claim, he reversed this marshalling, placing his own arms on the dexter, and those of Castile and León on the sinister. He thus continued to signal his alliance with the Castilian royal house, while abandoning any claim to the throne. There is, however, evidence that he may occasionally have used this second marshalling at earlier dates. In addition to his royal arms, Gaunt bore an alternative coat of "Sable, three ostrich feathers ermine".