The Shōwa period was the time in Japanese history when Emperor Hirohito reigned over the country, from December 25, 1926 to January 7, 1989. It is the longest period of all Japanese emperors.
The early part of Hirohito's reign was characterized by a period of imperialism. Following the surrender of Japan in the Second World War, the Occupation of Japan lasted until 1952. After the Treaty of San Francisco was enacted, Japan was free and has been in a period of relative peace ever since.
The word Shōwa means "enlightened peace". Showa and Shouwa are alternative Romanizations. It is pronounced sho wa, with an elongated o in the first syllable.