Question

What did they call the red Sea back then

Answer 1

The first people known to explore the Red Sea were the Ancient Egyptians, who explored the area c. 2500 BC while looking for commercial routes southward. So how did the Red Sea get its name? Theories abound, but no one knows for sure.

It could be from the red-hued "sea sawdust," a type of bacteria that grows near the water's surface. Some historians believe the Red Sea is named for the Himyarites, a group who once lived along it's shores.  Others believe that the "red" in Red Sea is actually a designator of the Sea's location relative to the ancient Mediterranean world - to the South. In ancient languages, the colors black, red, green, and white referred to North, South, East, and West, respectively.