Henry of Grosmont, 1st Duke of Lancaster

Henry of Grosmont KG, Duke of Lancaster, was born around 1310 at Grosmont Castle in Monmouthshire, Wales. He was the son of Henry, 3rd Earl of Lancaster, and Maud Chaworth. As a member of the House of Plantagenet, he was closely related to the English royal family, being a second cousin to King Edward III.

Henry became one of King Edward III's most trusted captains during the early phases of the Hundred Years' War. He distinguished himself with a victory at the Battle of Auberoche. In 1348, he was a founding member and the second knight of the Order of the Garter. In 1351, he was created Duke of Lancaster, a title that came with palatinate powers over the county of Lancashire.

Henry was a skilled diplomat and soldier, participating in numerous military campaigns, including the Siege of Berwick and the Battle of Halidon Hill during the Second War of Scottish Independence. He also took part in the Battle of Sluys and the Siege of Calais. His financial acumen was demonstrated when he brokered loans for King Edward III and raised funds to secure the release of the royal crown and jewels.

In addition to his military and diplomatic achievements, Henry was an accomplished writer. He authored the devotional treatise Livre de Seyntz Medicines, which revealed his intelligence and reflective nature. The book, written in 1354, shows that he suffered from gout and provides insights into his religious beliefs and personal reflections.

Henry married Isabel of Beaumont, and they had two daughters: Maud, who became Duchess of Bavaria, and Blanche, who became Duchess of Lancaster. Blanche married John of Gaunt, the third surviving son of Edward III, which eventually led to the vast Lancaster inheritance being merged with the Crown.

Henry was involved in the establishment of Corpus Christi College, Cambridge, in 1352, demonstrating his commitment to education and religious institutions. He was also a key negotiator for the Treaty of Brétigny, which marked the end of the first phase of the Hundred Years' War, securing favorable terms for England.

Henry of Grosmont died on 23 March 1361 at Leicester Castle, possibly due to the plague, and was buried in the Church of the Annunciation of Our Lady of the Newarke. His titles and estates were inherited by his son-in-law, John of Gaunt, through his daughter Blanche.