'Old John of Gaunt, time-honour'd Lancaster' John of Gaunt (1340-1399) was the son of one king and the father of another. He claimed a Spanish kingdom via his wife, daughter of King Pedro the Cruel. He was the wealthiest, most powerful and most hated man in England for decades. He had a famous and enduring love affair with his mistress Katherine Swynford, whom he later married. He was sometimes the ally and sometimes the enemy of his capricious nephew...