Imam.
General Zia Ul Haq implemented some islamic laws in Pakistan .
Emirate
Islam is a religion, not a country. So if a country chose Islam as a religion, the ruler's title would depend on the country's politics. It could be president, king, etc. In the past they used the equivalent of these titles in Arabic like Khalifa or Sultan which they both translates to ruler.
The Islamic Empires had a heredity system of succession of rulers, which meant that rule was passed to the children of the former ruler. However, if the ruler had no children, then there was much dispute and fighting over the throne.
A Caliph or khalifa is a sort of religious dictator, an Islamic ruler, considered to be the political-religious leader of an Islamic community of believers, ruling in accordance with Islamic law.
Mohammed, the final Islamic prophet was Islam's first leader.
Sultan Shah hab UD Din Ghori was the first ruler who laid the foundations of first ISLAMIC STATE in SUB CONTINENT in 1174.
Muhammads (saw) Islamic state is basically the Khilafah and a Khalif is the ruler and the Khalif should be appointed by Allah and should be infallible so he dont judge wrong amongst the people
It depends on the Islamic Empire in question. (There have been over 25 distinct Islamic Empires.) Usually this position was taken by a Caliph, but there a significant number of Islamic Empires, especially later in history, where the Caliph was exclusively a religious leader and it was the Sultan who ruled from a political perspective.
Tamerlane ruler of a Mongol Khanate based in Somarkand.
The government of Afghanistan is an Islamic Republic with an elected President.