Passage: Upon his return, Robert – urged by Flambard and several Anglo-Norman barons – claimed the English crown, on the basis of the short-lived agreement of 1087, and in 1101 led an invasion to oust his brother Henry.  He landed at Portsmouth with his army, but the lack of popular support among the English (Anselm, the archbishop of Canterbury, was decidedly against him and the Charter of Liberties issued at Henry's coronation was well liked) as well as Robert's own mishandling of the invasion tactics enabled Henry to resist the invasion. Robert was forced by diplomacy to renounce his claim to the English throne in the Treaty of Alton. It is said that Robert was a brilliant field commander but a terrible strategist in the First Crusade.

Question: Who championed a invasion to overthrow their brother henry?
Robert