John of Gaunt John of Gaunt John of Gaunt, Duke of Lancaster (6 March 13403 February 1399) was an English prince, military leader, and statesman. He was the third of the five sons of King Edward III of England who survived to adulthood. Due to his royal origin, advantageous marriages, and some generous land grants, Gaunt was one of the richest men of his era, and an influential figure during the reigns of both his father, Edward, and his nephew, Richard II. As Duke of Lancaster, he is the founder of the royal House of Lancaster, whose members would ascend to the throne
John of Gaunt in Jure uxoris by right of his second wife, Constance of Castile, whom he had married in 1371. However, crisis ensued almost immediately in his absence, and in 1387 King Richard's misrule brought England to the brink of civil war. Only John, on his return to England in 1389, succeeded in persuading the Lords Appellant and King Richard to compromise to usher in a period of relative stability. During the 1390s, John's reputation of devotion to the well-being of the kingdom was largely restored. During his second marriage, John of Gaunt had entered into an extra-marital love affair with Katherine