The history of the Arab states has never known kings, kings or emperors, their political system and state system for many centuries are completely subordinate to the norms and dogmas of the dominant religions, in most states it is Islam.
In Arab countries, the designation of the country is also indicated by the name of the ruler.
Caliphs
The very name of the caliph means that this ruler is a representative of both secular and religious rule in the country. According to legend, the caliphs were governors of the Prophet Muhammad. The Caliph is the title of the ruler of a state in which secular power is inseparable from the religious component.
Currently, the countries of the Arab world have various forms of government.
So, in Qatar in 1970 a constitution was adopted, according to which representatives of the principalities - the emirates chose from their composition the supreme ruler - the president for a period of five years. The president is the head of state and has all the powers stipulated by the constitution of the country.
Sheikhs
The dynasties of the rulers of Kuwait, Bahrain, the United Arab Emirates appeared at a time when tribes were settled on their territories. Over time, the tribes divided, chose their tribal leaders - sheikhs. The sheikhs, who had a stronger influence than the other tribal leaders, strengthened their power, asserting their advantage among the other tribes. This process continued until one of the powerful sheikhs established a dynasty from his family. This dynasty enjoyed the right to inherit tribal rule. So the current ruler of Bahrain is the hereditary ruler of the dynasty, which was founded in the eighteenth century.
Emirs
In all monarchies in the hands of the head of state there is a single power, in fact, turning this state into a unitary monarchy. It could be the king. As in Morocco and Jordan, the emir is in the United Arab Emirates. However, you need to understand that the title "king" is not Arabic, it was introduced by the colonialists and those countries that at one time carried out expansion in the country, for example, Great Britain in Morocco.
In the United Arab Emirates since 1971, the ruler of the state is the emir of the largest emirate of the country of Abu Dhabi. This title is hereditary for the dynasty of these emirs and is passed on from generation to generation. The current ruler is the emir - Sheikh Zayed Ben Sultan Al Nahyan. All seven emirates, into which the country is divided, are independent administrative territories, which are subordinated to the emperor, the supreme ruler of the UAE.