Raqqa

Raqqa was known as Kallinikos before coming under Muslim rule.

The city was recognized as one of the few official cross-border trading posts between the Byzantine Empire and Sassanid Persia.

The al-Rafiqah mosque in Raqqa was the first mosque built entirely from scratch on a coherent plan.

Raqqa's location allowed it to be a vital river port on the upper Euphrates, remaining ice-free throughout the year.

The city had a thriving industrial complex that included pottery and glass production.