There’s a name that you should remember: Abu Bakr al-Baghdadi, the commander of the Islamic State in Iraq and Syria (ISIS), whose fighters now control large swaths of Iraq.

There are few photos of al-Baghdadi, and even fewer details about his life are well-known. But as Iraq is engulfed by conflict and the country’s second largest city fell to Sunni extremists, the influence of Islamic terrorism’s newest star is set to grow.

TIME’s International Editor Bobby Ghosh explains the danger behind al-Baghdadi’s rise to power, and what that means for both Europe and the United States.

Write to Francesca Trianni at francesca.trianni@time.com.