Princess Ileana of Romania, also known as Mother Alexandra, was the youngest daughter of King Ferdinand I of Romania and his consort, Queen Marie of Romania. She was a great-granddaughter of Emperor Alexander II of Russia, King Ferdinand II, Queen Maria II of Portugal, and Queen Victoria of the United Kingdom. She was born as Her Royal Highness Princess Ileana of Romania, Princess of Hohenzollern-Sigmaringen.

Ferdinand I, nicknamed Întregitorul, was King of Romania from 1914 until his death in 1927. Ferdinand was the second son of Leopold, Prince of Hohenzollern, and Infanta Antónia of Portugal, daughter of Ferdinand II of Portugal and Maria II of Portugal. His family was part of the Catholic branch of the Prussian royal family Hohenzollern.