WikiIslam:Sandbox/Arab Prophets
There were many people who claimed prophethood in Arabia.
Before Muhammad
According to Islamic sources, the byzantine emperor Heraclius considered the non-existence of Arab prophets before Muhammad as a proof of Muhammad's prophethood:
...Heraclius said, 'Did anybody else (amongst you) ever claimed the same (i.e. Islam) before him? I said, 'No.'
...Then I asked you whether anyone had said this statement before him; and you denied that. Thereupon I thought if somebody had said that statement before him, then I would have said that he was but a man copying some sayings said before him."
But this is debunked by the Quran itself, because the Quran speaks about Arab prophets before Muhammad.