In 1198, King Henry II of England invaded Ireland and gave the part of it he controlled to his son John as a Lordship when John was just 10 in 1177. When John succeeded to the English throne in 1199, he remained Lord of Ireland thereby bringing the kingdom of England and the lordship of Ireland into personal union. Successive Kings of England also had the title of Lord of Ireland until the title was abolished by Henry VIII, who was made King of Ireland by the Parliament of Ireland by the Crown of Ireland Act 1542.
Henry of Bolingbroke, born at Bolingbroke Castle in Lincolnshire, was King Henry IV of England and Lord of Ireland from 1399 to 1413, and asserted the claim of his grandfather, Edward III, to the Kingdom of France. His father, John of Gaunt, was the fourth son of Edward III and the third son to survive to adulthood, and enjoyed a position of considerable influence during much of the reign of Henry's cousin Richard II, whom Henry eventually deposed. Henry's mother was Blanche, heiress to the considerable Lancaster estates, and thus he became the first King of England from the Lancaster branch of the Plantagenets and the first King of England since the Norman Conquest whose mother tongue was English rather than French.
The Royal style of King Henry IV was "Rex Angliae et Franciae et Dominus Hiberniae" (King of England and of France and Lord of Ireland).