The brutal Islamic group started off as an al Qaeda splinter cell, but over the years it made a name for itself simply owing to its barbaric ways.
By the end of 2013, the Islamic State, which used to known as the Islamic State of Iraq and the Levant (ISIL), had become a burden on its parent terrorist organisation Al Qaeda. The Syrian rebel group al Nusra constantly found ISIS coming in its way and the two often ended up in bloody killings.
Finally by 2014, Al Qaeda severed all its ties with the group as it became clear that ISIS was growing bigger than its parent organisation.
From the start, the ISIS, which stands for the Islamic State of Iraq and Syria, aimed to create an Islamic state across Sunni areas of Iraq and in Syria.
Today ISIS is known for killing dozens of people at a time and carrying out public executions, crucifixions and other acts of monstrosity. Additionally, it has also been able to build for itself an Islamic country that is governed by the principles of Sharia.
The group currently controls hundreds of square kilometres of land area in both Iraq and Syria. It ignores international borders and has a presence from Syria's Mediterranean coast to south of Baghdad.
Cases of beheading and stoning have been reported from several areas under the ISIS control.
The group currently is listed as one of the richest terrorist organisations in the world. ISIS's initial strategy for revenue was through extortion and robbery, but it slowly shifted to capturing oil fields in Syria and Iraq.
The group's leader and self-declared caliph of Islamic State Abu Bakr al-Baghdadi is a shadowy figure. There is little that is known about al-Baghdadi, but a biography posted on jihadist websites in 2013 claim that he has a doctorate in Islamic studies from a university in Baghdad.
Al-Baghdadi spent four years in Camp Bucca, which was a US-run prison in southern Iraq and was released in 2009. Reports claim that it was in Camp Bucca that the several top-brass of ISIS met and later joined forces to establish the Islamic caliphate.
After ISIS declared the creation of the so-called "Islamic State," he began using the name Al-Khalifah Ibrahim, and now goes by that name with his followers.
2014: Timeline and Facts on the Rise of a Terrorist Organisation - ISIS- which now runs a country