Political aspects of Islam are derived from the Qur'an, the Sunna (the sayings and living habits of Muhammad), Muslim history, and elements of political movements outside Islam.Traditional political concepts in Islam include leadership by elected or selected successors to the Prophet known as Caliphs, (Imamate for Shia); the importance of following Islamic law or Sharia; the duty of rulers to seek Shura or consultation from their subjects; and the importance of rebuking unjust rulers.A significant change in the Islamic world was the abolition of the Ottoman caliphate in 1924.