“Pitt is to Addington, As London is to Paddington” quipped the mean Canning, but that was unfair. Addington (1757-1844) was a better financier than Pitt, getting the wartime budget close to balance in 1803-04 through applying withholding to the new income tax. His Peace of Amiens of 1802-03 was only a temporary truce, during which Addington achieved a notable election victory, but that was Napoleon’s fault not his. He brought together most of the ministerial team that was eventually to end the war successfully. Addington was generally a good administrator; his one major mistake was to appoint to the Admiralty Earl St. Vincent (1735-1823), a naval hero but a poor administrator and an unpleasant personality with the usual Whig taste for nepotism and jobbery. Later, as Viscount Sidmouth, Addington was a notably successful Home Secretary and a valued member of Liverpool’s Cabinet.
Like the other prime ministers Pitt through Liverpool, Addington held office in an exceptionally difficult period; in contrast to the Victorians, who mostly had it very easy. He thus deserves to rank above the middle of the pack, somewhere in the 20s.
More biographical information can be found in Addington's Chronology entry