On September 16, 1915, the Scottish Women's Hospitals unit in Ostrovo, Serbia, was treating casualties from the Serbian army's retreat from the Austro-Hungarian and Bulgarian advance. The unit had been organized by Dr. Elsie Inglis and funded entirely by women's suffrage organizations, because the British War Office had rejected her offer of medical units staffed by women with the response: "My good lady, go home and sit still."

Inglis was born in 1864 in Naini Tal, India, where her father was in the Indian Civil Service, and educated in Edinburgh, where she became one of the first women to qualify as a physician in Scotland. She cofounded the Edinburgh School of Medicine for Women and was an active suffragist.

When war broke out in 1914, she proposed that the Scottish Federation of Women's Suffrage Societies organize and fund all-female medical units for the front. The British War Office refused. The French, Serbian, Russian, and Belgian governments accepted. She deployed units to France, Serbia, Russia, and Romania. The Serbian unit treated 30,000 patients in the first year.

In 1916, the Austro-Hungarian army overran the unit's position in Serbia. The medical staff were taken prisoner. Inglis refused to evacuate when offered the chance, remaining with her patients. She was eventually repatriated to Britain, returned immediately to Russia with a new unit, and died of cancer in November 1917, the day after returning from Russia.

The British government refused to fund her units throughout the war. The units treated hundreds of thousands of patients on multiple fronts.