Really? I'm curious as to where the Shia were at this point.
Well, most Arabs in southern Mesopotamia, the (southern) Persian Gulf coast, and the islands in the Persian Gulf were Shi'ites, just like a good number of poweful tribes in the mountains of Yemen.
There were also Shi'a communities among the Persians: from the 9th to the 11th or 12th century, there was a Zaydi Shi'ite state in northwestern Persia; the Buwayhids, who were a powerful Persian clan that controlled much of Mesopotamia and western Persia during the 10th and early 11th centuries, were Zaydi Shi'ites; a good number of the Nizari Ismaili's (a.k.a. Assassins) were Persians.
And until the fall of the Fatimid Caliphate in the 12th century, there were still Shi'ite communities in North Africa, allthough Shi'a Islam seems to have disappeared in Egypt relatively soon after the fall of the Fatimids.
However, as a result of Fatimid influence, there were (and still are) small Shi'ite communities and sects in Syria and the Levant.