The chronically ill heir of the Peelite Lord Aberdeen, Haddo suppressed his Conservative sympathies while his father was alive. He was returned for Aberdeenshire in 1854 but took no part in the debates on the Crimean war that led to the fall of Aberdeen’s government. A devout Evangelical, Haddo repeatedly attempted to prevent public money going to art schools that employed nude models. His obsession with the issue prompted one observer to describe him as ‘melancholy mad’. He succeeded as 5th earl of Aberdeen in 1860.