Henry Addington was born into a middle-class family in 1757. He was educated at Reading School, Winchester, and Brasenose College, Oxford. His father was physician to Pitt the Elder, and consequently Addington was a childhood friend of Pitt the Younger.

Addington was elected to the House of Commons in 1784 as Member of Parliament for Devizes. He aligned himself with the Pittites. Though he was not a particularly strong orator, he was well liked by MPs and Pitt asked him to be Speaker of the House of Commons, a role he served in from 1789 to 1800. In 1798, Addington suggested to Pitt a scheme of voluntary contributions that raised considerable sums for the war effort.

Addington’s support and friendship towards Pitt continued throughout this period. In 1800, Pitt took refuge in Addington’s Reading estate to recover from health problems. Pitt liked Addington, and it seems likely that he saw him as an interim leader if he ever needed a break.

In February 1801, Pitt resigned, ostensibly over the matter of Catholic emancipation, though he had been losing his control for a while. He recommended that Addington replace him.

Several Pittites refused to join Addington’s government, including William Grenville, Henry Dundas, and George Canning. The absence of a strong speaker, and Addington’s habitual weakness in arguing for his policies, would trouble his ministry throughout. Nevertheless, many found the warm and pleasant Addington a welcome relief after Pitt’s rather colder and more forceful manner.

The first priority was peace with France. The coalition powers had tired of trying to destroy the French Revolution and French armies had counterattacked, winning victories and conquests. At sea, the British were triumphant, having seized colonies themselves and defeated the French navy, but the redcoats made no progress on land. The new French ruler, Napoleon Bonaparte, who had seized power in a coup in 1799, appeared willing to end the war. On 25 March 1802, the Treaty of Amiens was signed, ending the French Revolutionary Wars.

However, the peace did not hold. Just over a year later, in May 1803, after disputes over the French invasion of Switzerland and the unwillingness of the British to evacuate Malta, Addington declared war on France. To announce the decision in the Commons, he dressed in his militia uniform, likely intending to convey a martial spirit, though eyewitnesses do not seem to have agreed. More practically, Addington mobilised resources to defend against the possibility of invasion and began to make overtures to the continental powers for a formal alliance. He also reinstituted income tax, but on a much more solid basis, reliant now on deduction at source (rather than voluntary compliance).

But Addington was a peacetime administrator and not a war leader. He did not inspire his followers, let alone Parliament or the country at large. Pitt waited as Addington’s parliamentary majority withered away. On 29 April 1804, accepting the inevitable, Addington resigned, and Pitt was reinstated as Prime Minister.

In 1805, Addington was elevated to the House of Lords as Lord Sidmouth. He returned to government in 1812 as Lord President and then Home Secretary (1812-22). His tenure would be a troubled one. He dealt with disorder by suspending habeas corpus in 1817 and instituting the Six Acts in 1819. He would also be blamed for the Peterloo massacre, especially after he conveyed the thanks of the Prince Regent to the magistrates for their ‘preservation of the public peace’. In 1824, he disagreed with the recognition of the rebellious Spanish colonies in Latin America and resigned.

Addington was also a supporter of London’s Foundling Hospital for abandoned babies.

Addington married Ursula Mary Hammond in 1781 and they had eight children, seven of whom survived to adulthood.

He died in 1844.