Who held him and what was given/done to secure his release?

Via Al Jazeera:

An American journalist kidnapped nearly two years ago has been freed in Syria and handed over to UN representatives, after Qatari mediation helped lead to his release.

Peter Theo Curtis was freed from captivity on Sunday, after reportedly being abducted in Antakya, Turkey, where he planned to enter Syria in October 2012.

Footage of the the American was released on June 30, showing a disheveled Curtis with long hair and beard, but appearing to be in good health.

Speaking in a video obtained by Al Jazeera, Curtis read from a prepared script stating his name and profession, saying he was a journalist from Boston, Massachusetts.

Commenting on his treatment, Curtis said he “had everything” he needed and “everything has been perfect, food, clothing, even friends now”.

Al Jazeera’s Rula Amin, reporting from Beirut, said the Islamic State group has used hostage taking to extract money from governments, but it was still unclear which group was behind Curtis’ kidnapping.

“In many cases prisoners change hands between groups, so it’s very hard to track down which group holds which hostage,” she said.