Henry Addington, the son of Lord Chatham's physician, was a childhood friend of William Pitt the Younger. He was elected to the Commons in 1784, and became Speaker in 1789. In March, 1801, Pitt was forced to resign from office due to his call for Catholic emancipation, and Addington was chosen to succeed him.
Addington's ministry was most notable for the negotiation of the Treaty of Amiens, in 1802 in which an unfavorable peace was agreed to with France. It quickly broke down, and Addington's poor management of the war led to Pitt's return to power the next year. Addington remained an important political figure, however. Created Viscount Sidmouth, he joined Pitt's Cabinet as Lord President, and later served in the Ministry of all the Talents as Lord Privy Seal and Lord President.
When the Pittites returned to power in 1807, Sidmouth returned to opposition, but returned to government as Lord President in March, 1812, and, in June of the same year, became Home Secretary. As Home Secretary, Sidmouth brutally crushed radical opposition, being responsible for the suspension of Habeas Corpus[?] in 1817, and the passage of the repressive Six Acts in 1819. Sidmouth left office in 1822, succeeded as Home Secretary by the much more competent Robert Peel, but continued to be active in politics for some time, fruitlessly opposing British recognition of the South American republics, Catholic Emancipation, and the Reform Act of 1832.