source: These regions therefore had a diverse range of different peoples and were, to some extent, unified by an Islamic culture built on both religious and civic foundations.
target: These regions had a diverse range of different peoples. They were, to some extent, unified by an Islamic culture. That culture was built on both religious and civic foundations.
references: These regions had a diverse range of different peoples. They were, to some extent, unified by an Islamic culture. That culture was built on both religious and civic foundations.