(CNN) -- Here's a look at Islamic State in Iraq and Syria (ISIS).

Facts: 
Started as an al Qaeda splinter group.

Also known as Islamic State in Iraq and the Levant and Islamic State (IS).

Led by Abu Bakr al-Baghdadi.

The aim of ISIS is to create an Islamic state across Sunni areas of Iraq and in Syria.

ISIS is known for killing dozens of people at a time and carrying out public executions, crucifixions and other acts. It has taken over large swaths of northern and western Iraq.

The group currently controls hundreds of square miles. It ignores international borders and has a presence from Syria's Mediterranean coast to south of Baghdad. It rules by Sharia law.

ISIS's initial strategy for revenue was through extortion and robbery. Recently, al-Baghdadi's strategy shifted to generating resources through large-scale attacks aimed at capturing and holding territory.

Unable to serve under the new Iraq government after Saddam Hussein's military was disbanded, former Iraqi soldiers became ISIS fighters, according to Middle East expert Fawaz Gerges.