I’m still translating the world history of the 10th century Arabic Christian writer Agapius. I’ve just come across this:
This sea contains also on the coast of Persia a gulf which is called the Persian Gulf; its length is 1,400 miles, its width at the beginning is 500 miles and its end is 150 miles. Between these two gulfs is the country of Hedjaz and Yemen; the distance between the gulf of Aylah and the Persian Gulf is 1,500 miles.
Today we encounter Arabs determined to rename the Persian gulf as “the Arabian sea.” But here is evidence that in the Middle Ages they had no such qualms.
He also mentions Britain!