http://en.wikipedia.org/wiki/Khosrau_II#Muhammad.27s_letter_to_Khosrau_II
Had Khosrau sent a sizable force, and Mohammed ended up dead, or somewhere far away (modern day Kazakhstan? China?), not only would the Persians, and subsequently Zoroastrianism, unknowingly avoid their destruction (almost completely in the latter case, for pedantics), but would have many more resources with which to fight the Byzantines. My question is, specifically, what would the failure of the Arab tribes to unite mean for medieval Europe and Middle East?
I imagine Charlemagne isn't crowned Emperor of the Romans as the Byzantines are much more prominent, retaining most of Justinian's recon quests, so there also wouldn't be a HRE. Somewhat of interest, the Tang Dynasty wouldn't be blocked by the Arabs at the Talas River, so a westward-expanding China as far west as the eastern shores of the Caspian might be possible.
Had Khosrau sent a sizable force, and Mohammed ended up dead, or somewhere far away (modern day Kazakhstan? China?), not only would the Persians, and subsequently Zoroastrianism, unknowingly avoid their destruction (almost completely in the latter case, for pedantics), but would have many more resources with which to fight the Byzantines. My question is, specifically, what would the failure of the Arab tribes to unite mean for medieval Europe and Middle East?
I imagine Charlemagne isn't crowned Emperor of the Romans as the Byzantines are much more prominent, retaining most of Justinian's recon quests, so there also wouldn't be a HRE. Somewhat of interest, the Tang Dynasty wouldn't be blocked by the Arabs at the Talas River, so a westward-expanding China as far west as the eastern shores of the Caspian might be possible.