Robert Peel

Peel secured repeal of the Corn Laws in 1846 with opposition help, breaking with the protectionist majority of his Conservative MPs. His government then fell on an Irish coercion bill, not on the repeal vote itself. Protectionist Conservatives joined other opponents to defeat him, and he resigned. The distinction matters: he achieved the central policy change while losing the parliamentary coalition that made continued government possible. His supporters subsequently developed into a separate Peelite grouping.