This timeline of women in warfare and the military (1900–45) deals with the role of women in the military around the world from 1900 through 1945. By the end of the 19th century, women in some countries were starting to serve in limited roles in various branches of the military. The two major events in this time period were World War I and World War II. Please see Women in World War I and Women in World War II for more information.
Australia: More than 3,000 Australian civilian nurses volunteer for active service.
Britain: The British form the Women's Army Auxiliary Corps in 1917; the Corps is renamed the Queen Mary's Army Auxiliary Corps in 1918. Members of this corps serve as clerical staff, cooks and medical personnel. It is disbanded in September 1921. Also in 1917, the British form the Women's Royal Naval Service as a branch of the Royal Navy. Members of this corps serve as clerks, cooks, electricians and air mechanics. The British disband the unit in 1919.
Canada: Over 2,800 women serve in the Royal Canadian Army Medical Corps during the war. Women also receive training in small arms, first aid and vehicle maintenance in anticipation of being used as home guards.
New Zealand: Nurses in the New Zealand Army Nursing Service serve on hospital ships and in hospitals at the front in France.
Romania: During the 1916 battle in the Jiu Valley, Ecaterina Teodoroiu transfers from the Romanian Army's all-female nurse corps to the Reconnaissance Corps. She is taken prisoner while serving as a scout, but escapes after killing several German soldiers. In November she is wounded and hospitalized, but returns to the front; she is decorated, promoted to Sublocotenent (second lieutenant) and given the command of a 25-man platoon. For her valor she is awarded the Military Virtue Medal, First Class. On September 3, 1917 (August 22 Old Style) she is killed in the Battle of Mărăşeşti (in Vrancea County) after being hit in the chest by German machine-gun fire. According to some accounts, her last words before dying were "Forward, men, I'm still with you!"
Russia: Russia fields 15 formations of female battalions for several months in 1917; two (the 1st Russian Women's Battalion of Death and the Perm Battalion) are deployed to the front. By the end of the year, all battalions are dissolved.