“The Islamic State of Iraq and the Levant (the group’s original name) decided that anybody who utters their (old) name will get 70 lashes,” said Ghaida’a Al-Rasool, a doctor in Mosul. “Their new name is simply the Islamic State.”

The group has established Islamic courts controlled by muftis, or Muslim religious leaders. Fighters regularly drive through the streets in trucks using loudspeakers to inform residents about changes.

“They have told clothing merchants to sell what they have within 20 days and then only jubbas are allowed,” said Saad Al-Hayali, an engineer in Mosul, referring to flowing, one-piece robes worn by Muslims throughout the Middle East. “They have forbidden dressing rooms inside stores, too.”

More worrisome for residents is the Islamic State’s move to cleanse its strongholds. Christians and other minorities were given an ultimatum: Convert to Islam or face execution.