War still looked easy in 1914 when Sophie's brother, Kaiser Wilhelm II, went to war. Greece was bound by treaty to Serbia, an ally against Germany. Greece tried to remain neutral due to Sophie's Hohenzollern ancestry. She was one of her mother's loyal children and she was strongly pro-British. Greece entered the War as an ally and King Konstantinos and Sophia had to leave in 1917 regardless of her true sympathies. Anglo-Greek forces were on the verge of invading Hungary, a little-known but possibly decisive part of the carnage of that war. Her Wikipedia article is here.