Profile: David Haines
The British man being held hostage by self-styled Islamic State fighters in Syria is 44-year-old David Haines.
The father of two from Perth has more than 15 years' experience with a number of humanitarian agencies.
He has worked on projects in Libya, South Sudan and the former Yugoslavia.
He was taken hostage alongside an Italian aid worker in Syria last March - barely two weeks into his posting with a French relief agency, ACTED.
The pair had been working in the Atmeh refugee camp in the Idlib province, close to the Turkish border, supplying water, food and tents.
Mr Haines's Italian colleague, Federico Motka, was released in May this year.
Mr Haines attended the Perth Academy in Scotland.
Since 1999 he has held a number of positions with aid agencies around the world.
He worked with a German charity on post-war reconstruction projects in Croatia, including housing and demining. He was also involved in efforts to help displaced people to return to their homes.
In 2011 he became Head of Mission in Libya for Handicap International.
The following year he joined another agency, the Nonviolence Peaceforce (NP), and went to South Sudan.
There, he and other NP staff worked as unarmed civilian peacekeepers.
The NP has issued a statement since Mr Haines's name emerged in the public domain, saying it joined people around the world in pleas, thoughts and calls for his safe release.
Mr Haines's parents live in Ayr.