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 Another motive was John's conviction that it was only by making peace with France would it be possible to release sufficient manpower to enforce his claim to the throne of Castile. On his return from France in 1374, John took a more decisive and persistent role in the direction of English foreign policy. From then until 1377, he was effectively the head of the English government due to the illness of his father and elder brother, who were unable to exercise authority. His vast estates made him the richest man in England, and his great wealth, ostentatious display of it,