The most popular Arab account holds that the word "Arab" came from an eponymous father called Ya'rub who was supposedly the first to speak Arabic.
Abu Muhammad al-Hasan al-Hamdani had another view; he states that Arabs were called Gharab ("West") by Mesopotamians because Bedouins originally resided to the west of Mesopotamia; the term was then corrupted into "Arab".
In the pre-Islamic era, most Arabs followed polytheistic religions.
Some tribes had adopted Christianity or Judaism, and a few individuals, the hanifs, apparently observed monotheism.
This makes them the world's second largest ethnic group after the Han Chinese.