In 1915, during World War I, under the leadership of Joseph Trumpeldor, a Zion Mule Corps was founded and served with the British in the Gallipoli Expeditionary Force. This corps’ record for bravery helped break down British resistance to establishing of a Jewish Legion. Such a legion, the Royal Fusiliers, was organized in 1917 in London after much effort by Vladimir Jabotinsky. In 1918, recruiting for the Jewish Legion began in the United States. David Ben-Gurion, later Prime Minister of Israel, Yitzhak Ben-Zvi, and Pinhas Rutenberg were the chief architects of the Legion movement in the United States. The Jewish Legion numbered 5,000 and was a part of the British Army that wrested Samaria, the Galilee, and Trans-Jordan from the Turks. Another 5,000 men were due to join them, but the Armistice was proclaimed before their arrival.