 Kurdish rebellions against the Ottoman Empire go back two centuries, but the modern conflict dates back to the abolition of the Caliphate.During the reign of Abdul Hamid II, who was Caliph as well as Sultan, the Kurds were loyal subjects of the Caliph and the establishment of a secular republic following the abolition of the Caliphate in 1924 became a source of widespread resentment.The establishment of the Turkish nationalist state and Turkish citizenship brought an end to the centuries old "millet" system, which had unified the Muslim ethnic groups of the Ottoman Empire under a unified Muslim identity.