Joseph Chamberlain, the father of Neville Chamberlain. In OTL, he was a footnote in history, an obscure radical imperialist who started as one of the rising stars of the Liberal Party and ended a man who split his party and joined the Conservatives. Instead, he becomes Prime Minister in 1886 as a result of his "Imperial Sitting Bill". Please Note: This is the only Point of Divergence- every change in the timeline is a result of this- while it may not seem obvious at the moment, it all links in.