Son of a Liverpool merchant, educated at Winchester and Balliol College, Oxford, Cardwell became a Conservative MP in 1841. He followed the Peelite free traders after the party split of 1846. In ministerial posts under Aberdeen and Palmerston, including colonial secretary, he stood out as an administrative reformer. Gladstone's secretary at war from 1868, he ended flogging in the army and undertook major reforms. Infantry regiments were given territorial designations and linked to reserves, short service was introduced, and the commander‐in‐chief's office was brought under clearer ministerial authority. The abolition of purchase of commissions was controversial; when the 1871 Army Regulation Bill was blocked by the Lords, the change was implemented by royal warrant.