William Ewart Gladstone

Gladstone's commitment to Irish home rule split the Liberals in 1886. Dissenting Liberal MPs helped defeat his first bill, then fought the election against his policy as Liberal Unionists. He lost the election and the premiership, although he retained the leadership of the pro-home-rule Liberals and returned to government in 1892. This was a division within his political coalition rather than his own expulsion: adopting a defining policy left him without the united party support needed to govern.