Alfons R. of Hamburg, Germany (shown in this undated photo), converted to Islam at age 17. Later, he went to Turkey, then Syria, to join ISIS. He was killed this past summer. Courtesy of Manfred Karg hide caption

itoggle caption Courtesy of Manfred Karg

Kirkuk province's Kurdish governor, Najim al-Din Omar Karim (center, wearing a bulletproof vest), listens to a commander of the Kurdish Peshmerga forces as troops are deployed on the main road between Kirkuk, Mosul and Baiji in response to the offensive by ISIS, an extremist Islamist group. Marwan Ibrahim/AFP/Getty Images hide caption

itoggle caption Marwan Ibrahim/AFP/Getty Images