sentences:  He was succeeded at Babylon 5 by Captain John Sheridan.In 2260, Sinclair received a 900-year old letter from himself on Minbar, revealing that he was not the "reincarnation" of Valen, as the Grey Council believed, but in fact Valen himself.Armed with this knowledge, Sinclair took Babylon 4 back with him 1,000 years to aid the Minbari in their first war against the Shadows, and in so doing, fulfilled Minbari prophecy by becoming the One Who Was.