The Brotherhood Civil War was a conflict between the Brotherhood of Steel and a splinter group, the Brotherhood Outcasts. The conflict began in 2276, following a drastic shift in mission profile by Owyn Lyons. Soon after, a large group of Brotherhood loyalists, led by Protector Henry Casdin, broke off from the chapter and continued the Brotherhood's mission on their own. By 2287, the war had been over due to changes within the leadership of the chapter.