12 Jun 1859—18 Oct 1865: Viscount Palmerston - 37th British Prime Minister
Henry John Temple, 3rd Viscount Palmerston, (20 October 1784 – 18 October 1865) was a British statesman who served twice as Prime Minister in the mid-19th century. Palmerston dominated British foreign policy during the period 1830 to 1865, when Britain was at the height of her imperial power. He held office almost continuously from 1807 until his death in 1865. He began his parliamentary career as a Tory, defected to the Whigs in 1830, and became the first Prime Minister of the newly formed Liberal Party in 1859.
He had two periods in office, 1855–1858 and 1859–1865, before his death at the age of 80 years, a few months subsequent to victory in a general election in which he had achieved an increased majority. He remains, to date, the last Prime Minister to die in office.