hundred days

In European history, the period 20 March–28 June 1815, marking the French emperor Napoleon's escape from imprisonment on Elba to his departure from Paris after losing the battle of Waterloo on 18 June.

The phrase also describes other periods of new administration.

In 1898 Emperor Te Tsung of China attempted 100 days of reform (11 June–16 September), under the guidance of K'ang Yu-wei. In 1931 Benito Mussolini and G Forzano wrote The 100 Days. It is also applied to the reform period in the administration of US president F D Roosevelt from his inauguration on 4 March 1933 when much of the legislation for his New Deal programme was initiated. English prime minister Harold Wilson used the phrase in Purpose and Power 1966.