The English soldier-statesman John of Gaunt (1340-1399), 5th Duke of Lancaster, played an active part in military and political affairs.

Born in March 1340, John of Gaunt was the fourth son of Edward III and received his name from his birthplace, Ghent. He was created Earl of Richmond in September 1342. Trained in military skills, at the age of 19 he took part in an expedition to France, and on May 19, 1359, he married Blanche, younger daughter and coheiress of Henry of Lancaster. Through this marriage he was created Earl of Derby in April 1362 and in November Duke of Lancaster.

For the next years Lancaster was active in various military campaigns, serving under his brother Edward the Black Prince in Spain in 1367, as captain of Calais 2 years later, and in 1371 as lieutenant of Aquitaine. After the death of his first wife in September 1369, he married Constance of Castile in 1372, surrendered his title...