the Serbian Army begins. September 15–18 – WWI: Battle of Dobro Pole in the Vardar Offensive of the Balkans Campaign: The Allied Army of the Orient defeats Bulgarian defenders. September 18 – WWI: Battle of Épehy – British approach the Hindenburg Line along the St Quentin Canal. September 19 – WWI: The British Army's Egyptian Expeditionary Force launches the Battle of Megiddo, incorporating the Battle of Sharon, and the Battle of Nablus, an attack in the Judaean Mountains. This day are fought the Battle of Tulkarm, and the Battle of Arara, which break the Ottoman front line stretching from the Mediterranean coast to the Judaean Mountains, while the Battle of Tabsor extends into September 20. The Third Transjordan attack in the Jordan Valley begins. September 20 – WWI: The British Army's Desert Mounted Corps launches the Battle of Nazareth by 5th Cavalry Division (British Indian Army); Capture of Afulah and Beisan by the 4th Cavalry Division (British Indian Army); Capture of Jenin by the Australian Mounted Division, almost encircling the Yildirim Army Group still in the Judaean Mountains. September 25 – WWI: The Battle of Megiddo ends with the Battle of Haifa, Battle of Samakh, and Capture of Tiberias. The Third Transjordan attack ends with ANZAC Mounted Division victory at the Second Battle of Amman, with the subsequent capture at Ziza of the Ottoman II Corps, and more than 10,000 Ottoman and German prisoners. September 26 – WWI: The Meuse-Argonne Offensive begins, the largest and bloodiest operation of the war for the American Expeditionary Forces. The Capture of Damascus begins, with the Charge at Irbid by the 4th Cavalry Division. September 27 – WWI: The Battle of the Canal du Nord, launched by British and Empire forces, continues the advance towards the Hindenburg Line. The Battle of Jisr Benat Yakub, launched by the Australian Mounted Division, continues the advance towards Damascus. September 29 – WWI: Battle of St Quentin Canal begins; Allied forces advance towards the Hindenburg Line. Bulgaria requests an armistice. September 30 – WWI: The Charge at Kaukab is begun by units of the Australian Mounted Division. The Charge at Kiswe is begun by 4th Cavalry Division, continuing the Desert Mounted Corps' advance to Damascus. October October 1 – WWI: The Desert Mounted Corps captures Damascus. October 2 – WWI: The Charge at Khan Ayash is begun north of Damascus, by the 3rd Light Horse Brigade. October 3