Mullah Mohammad Omar

For more than two years, the leader of the Taliban was a dead man. Mullah Mohammad Omar’s rule over Afghanistan came to an end in late 2001, when his refusal to surrender Osama bin Laden in the wake of the 9/11 terrorist attacks triggered the U.S. assault that ended his Taliban regime. He later fled into the mountains on the back of a motorcycle. He was never seen in public again, but even amid periodic rumors of his death, he remained a unifying figure for the militants.

On July 29, Afghanistan announced that Omar had died in a Pakistani hospital in 2013. He is thought to have been in his 50s. It’s unclear why it took so long to confirm his death.

The militants named a new leader–Mullah Akhtar Mansoor–but news of Omar’s death has already exacerbated fissures in the Taliban’s top ranks, raising questions about the future of peace talks with the Afghan government. A fresh threat looms as the Islamic State of Iraq and Greater Syria advances beyond the Middle East. News of Omar’s death could help it recruit Taliban militants and further ignite an already volatile region.