On this day (27 April, 1909), the last Sultan/Caliph who exercised power in the Ottoman Empire, Abdülhamid II, was overthrown by the Young Turks.

http://lostislamichistory.com/the-last-great-caliph-abdulhamid-ii/

Armenian genocide:
The Armenian Genocide occurred during WWI, after Abdulhamid II was overthrown.