The Sunni extremist group currently wreaking havoc across Syria and Iraq announced it has established an Islamic caliphate across the two countries. Here's what you need to know.

What is a caliphate?

A caliphate is an Islamic state. It's led by a caliph, who is a political and religious leader who is a successor (caliph) to the Islamic prophet Muhammad. His power and authority is absolute.

How to use caliphate in a sentence (via CNN):

In a newly released audio message and written statement, purportedly from the official spokesman of ISIS, the group called on Muslims to swear allegiance to the caliphate..."

Why did ISIS declare a caliphate?

1. It was always their plan to do so. 

2. They've had enough success in capturing territory across Iraq and Syria to do so.

3. No one, especially the Iraqi government seems to be stopping them.

Who will be mad about this?

Everyone. Especially al-Qaeda and its other affiliates, who had planned to establish a caliphate of their own to restore the Islamic caliphate from the 7th century.

Would I want to live in a caliphate?

Doesn't sound great so far. According to reports, ISIS has been crucifying people.

Also, caliphates operate under Sharia law. Women are discouraged to leave the home unless necessary and they must be accompanied. Amputations are the punishment for stealing. Also, no dissent, drugs, alcohol, and cigarettes. For a full list, see here.

Is there a chance I may end up living in a caliphate?

It depends on where you live. For reference though, here's what ISIS plans to do between now and 2019.

Will the caliphate really spread that far?

Let's hope not. Also this, weird metaphors aside, doesn't bode well for the state's ambitions.