Henry of Almain was the song of one of the wealthiest men in Europe who joined what?
Henry of Almain: Henry of Almain (Anglo-Norman French: "Henri d'Almayne") (2 November 1235 – 13 March 1271) was the son of Richard, 1st Earl of Cornwall and his first wife Isabel Marshal. Richard, 1st Earl of Cornwall: Richard (5 January 1209 – 2 April 1272), second son of John, King of England, was the nominal Count of Poitou (1225-1243), Earl of Cornwall (from 1225) and King of Germany (from 1257). Richard, 1st Earl of Cornwall:  He was one of the wealthiest men in Europe and joined the Barons' Crusade, where he achieved success as a negotiator for the release of prisoners and assisted with the building of the citadel in Ascalon.
the Barons' Crusade