How was Léon Bourgeois awarded the Nobel Prize Peace?

Name: Léon Bourgeois.
Country: France.
Date of Birth: 21 May 1851.
Died: 29 September 1925.
Education: Université de Paris.
President: French Parliament, Conseil de la Société des Nations.
Known as: Prime Minister of France.
Noble Prize Year: Nobel Prize for Peace in 1920, for his longstanding contribution to the cause of peace and justice and his prominent role in the establishment of the League of Nations.