This Timeline Shows The Lightning Rise Of ISIS

It's been exactly one year since the extremist group known as ISIS changed its name to "Islamic State" and declared a caliphate in parts of Syria and Iraq. The militants symbolically marked the occasion by obliterating part of the border between the two countries.

Less than a month before, on June 10, 2014, the extremists had surprised the world by capturing Mosul, Iraq's second largest city, from a fleeing Iraqi army.

Take a look at the timeline below to learn more about some of the major events in the group's lightning rise.