William Pitt (28 May 1759 – 23 January 1806) was a British statesman who served as the last prime minister of Great Britain from 1783 until the Acts of Union 1800, and the first official prime minister of the United Kingdom from January 1801. He left office in March 1801, but served as prime minister again from 1804 until his death in 1806. He was also Chancellor of the Exchequer for all his time as prime minister. He is known as "Pitt the Younger" to distinguish him from his father, William Pitt the Elder, who had also previously served as prime minister from 1766-1768.
Pitt's premierships, which came during the reign of King George III, were dominated by major political events in Europe, including the French Revolution and the Napoleonic Wars. Pitt, although often referred to by historians as a Tory, or "new Tory", called himself an "independent Whig" and was generally opposed to the development of a strict partisan political system.
Pitt was regarded as an outstanding administrator who worked for efficiency and reform, bringing in a new generation of competent administrators. He increased taxes to pay for the great war against France and cracked down on radicalism.