To do that, the group has set up a generous welfare system to help settle and create lives for the thousands of jihadis - men and women - who have flocked to IS territory from the Arab world, Europe, Central Asia and the United States. From the day he declared the "caliphate" last summer, IS leader Abu Bakr al-Baghdadi urged not just fighters to come, but also doctors, engineers, administrators and other experts.
"It is not just fighting," said al-Homsi, who uses a nom de guerre. "There are institutions. There are civilians (that IS) is in charge of, and wide territories . It must help the immigrants marry. These are the components of a state and it must look after its subjects." Al-Homsi spoke in a series of interviews with The Associated Press by Skype, giving a rare look into the personal life of an IS jihadi.
The new IS elite is visible in Raqqa, the biggest city in Syria under the extremists' rule.
Luxury houses and apartments, which once belonged to officials from Syrian President Bashar Assad's government, have been taken over by the new IS ruling class, particularly Iraqis who serve as senior military commanders, according to a member of an anti-IS media collective in the city who goes by the name of Abu Ibrahim al-Raqqawi.
A nearby nature preserve to protect deer has been turned into a military zone and is off-limits to civilians. Upper-level commanders get a car and fuel expenses paid. IS fighters are not charged a new entry fee at city hospitals that is imposed on others. IS has set up an English language nursery for children of English-speaking jihadis and bus rides from Raqqa to Iraqi and Syrian halves of the "caliphate" are also on offer.
Raqqa lies near the center of IS-controlled territory and is thus cushioned from the fighting around its edges. Its supermarkets are well stocked, though only IS fighters can afford the more luxurious imports like Nutella, said al-Raqqawi. Senior IS figures also own most of the plentiful Internet cafes in the city, run by satellite, and sell Internet access to residents at home by the megabyte.
"The city is stable, has all the services and all that is needed. It is not like rural areas the group controls," al-Raqqawi said. "Raqqa is now the new New York" of the caliphate.
Helping fighters marry is a key priority. Aside from the normal stipend they receive, foreign fighters get $500 when they marry to help them put together their new household. Aymenn al-Tamimi, an expert on insurgent groups, said that when the IS took Iraq's second largest city Mosul last summer, one of the first things militants did was set up an Islamic court - not just to pass sentences under their strict version of Shariah but also "to give official Islamic State approval of marriages."
