Lord Liverpool
Robert Banks Jenkinson, 2nd Earl of Liverpool. The Prime Minister who led Britain from 1812 to 1827, taking in the phases of the Napoleonic Wars when the tide turned and Napoleon was defeated. Prior to this, he had served as Foreign Secretary under William Pitt the Younger and Henry Addington.
Lord Liverpool was conservative and reactionary in his politics, though being a skilled politician he also held the disparate conservative and liberal wings of the Tory Party together through his long tenure. Initially opposed to the abolition of the slave trade, he later changed his position and advocated all European countries abolish it at the Congress of Vienna in 1814.
His government's more hands-off approach to the war in Europe can be partially credited with victory, and more so with the post-war settlement at the Congress. However, when he is remembered in Britain it is chiefly with distaste for his very authoritarian domestic policy, going so far as to suspend habeas corpus and unlawful gatherings at times in the face of Radical and Luddite activity. This went so far as to make him and his cabinet the targets for (unsuccessful) assassination in the 1820 Cato Street Conspiracy. His policies were intensified after the enormously scandalous Peterloo Massacre of 1819, when cavalry charged a peaceful crowd protesting for parliamentary reform. The reaction against Liverpool is arguably one of the major causes of the Chartist movement.
Lord Liverpool was also one-eighth Indian (his great-grandmother being from India), therefore possibly making him a dubious candidate for Britain's first ethnic minority PM, in the unlikely event any ethnic minority wants to lay claim to his premiership.