Sultan

In recent years, the title has been gradually replaced by "king" by contemporary hereditary rulers who wish to emphasize their secular authority under the rule of law.

Local governors with administrative authority held the title of amīr (أمير, traditionally "commander" or "emir", later also "prince") and were appointed by the caliph, but in the 9th century some of these became de facto independent rulers who founded their own dynasties, such as the Aghlabids and Tulunids.

[6] The first major figure to clearly grant himself this title was the Ghaznavid ruler Mahmud (r. 998–1030 CE) who controlled an empire over present-day Afghanistan and the surrounding region.

[8][6] Soon after, the Great Seljuks adopted this title after defeating the Ghaznavid Empire and taking control of an even larger territory which included Baghdad, the capital of the Abbasid caliphs.

[6] While the Seljuks acknowledged the caliphs in Baghdad formally as the universal leader of the Muslim community, their own political power clearly overshadowed the latter.

[6] Views about the office of the sultan further developed during the crisis that followed the destruction of Baghdad by the Mongols in 1258, which eliminated the remnants of Abbasid political power.

Henceforth, the surviving descendants of the Abbasid caliphs lived in Cairo under the protection of the Mamluks and were still nominally recognized by the latter.

[9] As protectors of the line of the Abbasid caliphs, the Mamluks recognized themselves as sultans and the Muslim scholar Khalil al-Zahiri argued that only they could hold that title.

[11] In Kazakh Khanate a Sultan was a lord from the ruling dynasty (a direct descendants of Genghis Khan) elected by clans, i.e. a kind of prince.

[citation needed] In a number of post-caliphal states under Mongol or Turkic rule, there was a feudal type of military hierarchy.

These administrations were often decimal (mainly in larger empires), using originally princely titles such as khan, malik, amir as mere rank denominations.

In the Persian empire, the rank of sultan was roughly equivalent to that of a modern-day captain in the West; socially in the fifth-rank class, styled 'Ali Jah.