Ibrahim al-Badri, a run-of-the-mill Sunni Iraqi cleric, gained a degree from the University of Baghdad at a time when pedagogy there had collapsed because of the Saddam Hussein dictatorship and international sanctions. After 2003 he took the name Abu Bakr al-Baghdadi and turned to a vicious and psychopathic violence involving blowing up children at ice cream shops and blowing up gerbils and garden snakes at pet shops and blowing up family weddings, then coming back and blowing up the resultant funerals. This man is one of the most infamous serial killers in modern history, with the blood of thousands on his hands, before whom Jeffrey Dahmer and Ted Bundy fade into insignificance.

Al-Baghdadi leads the so-called Islamic State of Iraq and Syria (ISIS or ISIL), which today changed its name just to “the Islamic State.” And its members made a pledge of fealty to al-Baghdadi as the “caliph.” Let us please call it the “so-called Islamic State,” since it bears all the resemblance to mainstream Islam that Japan’s Om Shinrikyo (which let sarin gas into the subway in 1995) bears to Buddhism.
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After Ali’s assassination, the Umayyad kings ruled (661-750), and though some scholars have found that they claimed religious charisma, they were just Arab kings. A branch of the family of the Prophet tracing itself back to his uncle Abbas began making claims to rightful rule, however, and they were popular among the new converts from among the Persians in Iran, and in 750 they made a revolution against the Umayyads. They became the Abbasid caliphate, ruling until the Mongol conquest of Baghdad in 1258.
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Although subsequent sultans or secular emperors sometimes were termed “caliphs” in flowery style by their courtiers, I can’t find any evidence of anyone taking that sort of thing seriously. In the 18th century Ahmad al-Damanhuri, a rector of al-Azhar Seminary in Cairo, the foremost center of Sunni learning, wrote an essay in which he was frank that the caliphate ended in 1258, that the Mamluk ‘shadow caliphate’ hadn’t amounted to much, and that the Ottomans were kings, not caliphs. The Sunni caliphate had lapsed. He said, however, that some of the Ottomans were better and more just rulers, as secular monarchs, than some of the caliphs had been. I know of no reason to think that al-Damanhuri’s views weren’t the prevailing ones on the eve of Middle Eastern modernity. {Ahmad al-Damanhuri, al-Naf` al-ghazir fi salah al-Sultan wa al-wazir, Egyptian National Library, Taymur Ijtima`, MS 34, p. 10).

http://www.juancole.com/2014/06/caliphates-baghdadis-grandiosity.html