The history of Nili began during the First World War, when the Turks, who ruled Palestine, became involved in the conflict on the side of Germany and opposed Great Britain, France and Russia. In early 1915, just when Trumpeldor and Jabotinsky were in Egypt busy agitating for the creation of a Jewish unit in the British army, Sarah Aaronson was returning home to Palestine from Constantinople. The daughter of wealthy landowners from Zichron Yaakov, pioneers of the First Aliyah, she married and moved with her husband to Constantinople, but the marriage was unsuccessful. According to her upbringing Sarah gravitated toward country life. An excellent horsewoman, accustomed to riding freely on horseback in the hills surrounding the settlement, Sarah was suffocated by the pompous atmosphere that developed in the Jewish community of Constantinople, with many formalities like business cards and official receptions. When Turkey entered the war and sent its troops into Palestine, Sarah felt obliged to return home to her parents. Letters arrived from Zichron Yaakov indicating a deterioration in the situation. The Turkish authorities in Palestine first agreed to the creation of a Jewish militia, but then changed their minds and began to confiscate the weapons necessary for self-defense from the Jewish settlers.