Whose son's death brought titles to Edward III's most trusted captain?
Henry of Grosmont, 1st Duke of Lancaster Henry of Grosmont, 1st Duke of Lancaster, 4th Earl of Leicester and Lancaster, KG (c. 1310 – 23 March 1361), also Earl of Derby, was a member of the English nobility in the 14th century, and a prominent English diplomat, politician, and soldier. The son and heir of Henry, 3rd Earl of Lancaster, and Maud Chaworth, he became one of Edward III's most trusted captains in the early phases of the Hundred Years' War and distinguished himself with victory in the Battle of Auberoche. He was a founding member and the second Knight of the Order of the Garter in 1348, and in 1351 was created duke. An intelligent and reflective man, Grosmont taught himself to write and was the author of the book "Livre de seyntz medicines", a highly personal devotional treatise. He is remembered as one of the founders and early patrons of Corpus Christi College, Cambridge, which was established by two of the guilds of the town in 1352.
Roger Mortimer, 4th Earl of March Roger de Mortimer, 4th Earl of March and 6th Earl of Ulster (11 April 1374 – 20 July 1398) was a 14th-century English nobleman. He was considered the heir presumptive to King Richard II after the death in 1382 of his mother Philippa of Clarence (a granddaughter of King Edward III of England) until his own death in 1398.