Caliph Ibrahim's Brutal Moment

After an absence of 90 years, the ancient institution of the caliphate roared back into existence on the first day of Ramadan in the year 1435 of the Hegira, equivalent to June 29, 2014. This astonishing revival symbolically culminates the Islamist surge that began forty years ago. A Western analogy might be declaring the restoration of the Hapsburg Empire, which traced its legitimacy to ancient Rome.

Whence comes this audacious move? Can the caliphate last? What will its impact be?

For starters, a quick review of the caliphate (from the Arabic khilafa, meaning "succession"): according to canonical Muslim history, it originated in 632 CE, on the death of the Islamic prophet Muhammad, then spontaneously developed, filling the nascent Muslim community's need for a temporal leader. The caliph became Muhammad's non-prophetic heir. After the first four caliphs, the office became dynastic.

From the start, followers disagreed whether the caliph should be the most able and pious Muslim or the closest relative of Muhammad; the resulting division came to define the Sunni and Shi'i branches of Islam, respectively, causing the profound schism that still endures.

A single caliphate ruled all the Muslim lands until 750; but then two processes combined to diminish its power. First, remote provinces began to break away, with some – such as Spain – even creating rival caliphates. Second, the institution itself decayed and was taken over by slave soldiersand tribal conquerors, so that the original line of caliphs effectively ruled only until about 940. Other dynasties then adopted the title as a perquisite of political power.

The institution continued in an enfeebled form for a millennium until, in a dramatic act of repudiation, modern Turkey's founder, Kemal Atatürk, terminated its last vestiges in 1924. Despite several subsequent attempts to restore it, the institution became defunct, a symbol of the disarray in Muslim-majority countries and a yearned-for goal among Islamists.

And so matters remained for 90 years, until the group known as the Islamic State in Iraq and Syria (ISIS) issued a declaration in five languages (English version: This Is the Promise of Allah) proclaiming the founding of a new caliphate under "Caliph" Ibrahim...