- Source of Wealth: Inheritance
- Birth Place: Grosmont Castle, Grosmont, Monmouthshire
- Marital Status: Married (Isabel of Beaumont)
- Full Name: Henry of Grosmont, 1st Duke of Lancaster, 4th Earl of Leicester and Lancaster, Earl of Derby, KG
- Nationality: British
- Date of Birth: 1310
- Ethnicity: English
- Occupation: Diplomat, Politician, and Soldier
- Children: 2 (Blanche and Maud)
Henry of Grosmont is the 4th Earl of Leicester and Lancaster and 1st Duke of Lancaster of the Bolingbroke Castle in Lincolnshire who had an estimated net worth of $85.1 billion. He was a prominent English diplomat, soldier, politician and a member of the English royal family who became the most powerful and wealthiest peer of the realm. As the son of Maud Chaworth and Henry, 3rd Earl of Lancaster, he became one of the most trusted captains of King Edward III during the early phases of the Hundred Years’ War. He was able to distinguish himself because of his victory in the Battle of Auberoche. He eventually became the founding member as well as the second Knight of the Order of the Garter in the year 1348. He became the Duke of Lancaster in the year 1351. Since Grosmont was a reflective and intelligent man, he taught himself to write and eventually became the author of the highly personal devotional treatise Livre de seyntz medicines. People remembered him as one of the early patrons and founders of the Corpus Christi College, Cambridge, that was established by the town’s two guilds in the year 1352.
After he returned to England in November 1360, he fell ill the following year and eventually died at the Leicester Castle on March 23, 1361. The possible cause of his death was the plague that came to England during that time. He was buried in Leicester’s Church of the Annunciation of Our Lady of the Newarke. He built this within the charitable and religious institution that his father founded next to the Leicester castle where his father was buried.