What was officially initiated by Sherif Hussein bin Ali at Mecca on 10 June 1916, and was part of the Siege of Medina that occurred during World War I?
Siege of Medina: Medina, an Islamic holy city in Arabia, underwent a long siege during World War I. Siege of Medina:  Sharif Hussain of Mecca revolted against the caliph and the Ottoman Empire which, under the leadership of the nationalistic Young Turks, had ignored the wishes of the Caliph and sided with the Central Powers. Arab Revolt: The Arab Revolt (Arabic: الثورة العربية‎ ‎ , "al-Thawra al-‘Arabiyya "; Turkish: "Arap İsyanı" ) or Great Arab Revolt (Arabic: الثورة العربية الكبرى‎ ‎ , "al-Thawra al-‘Arabiyya al-Kubrā ") was officially initiated by Sherif Hussein bin Ali at Mecca on 10 June 1916 (9 Sha'ban of the Islamic calendar for that year) although his sons ‘Ali and Faisal had already initiated operations at Medina starting on 5 June with the aim of securing independence from the ruling Ottoman Turks and creating a single unified Arab state spanning from Aleppo in Syria to Aden in Yemen.
Arab Revolt