>>17975624
>northern parts of Iran
It was present in in NW Iran, NE Iran, and Southern Iran too though. Iran in general was filled with shia sects some orthodox and others heterodox or even outright heretics
>>17975256 (OP)
It wasn't irrelevant
Before the Seljuks shia dynasties were ruling the middle east. You had the fatimids in Egypt and North Africa, the shia arab emirates in Arabia, Iraq, and Syria, and then the twelver and zaydi dynasties in Iran. After the Seljuks you had the Nizari Ismailis enter the scene with shia dynasties continuing up north in the Alborz region. After this the mongols conquered the middle east and the existing shia sects took the opportunity to expand. Some new sects were formed such as Hurufism which spread far and wide and politically you had states like the sarbadars forming. The Safavids were active in this time period as well. In this time period the zaydis and ismailis declined while the twelvers and their derivative groups expanded. In Iraq a rival to the safavid the Musha'sha took control of southern iraq. We can observe the growth of the shia in this time period from their interactions with the political authorities. The Khwarezmians courted them once they started butting heads with the Abbasids, The Abbasids courted them in order to claw their way to some measure of independence with the Abbasid Caliph al Nasir being the prime example. They competed with their rivals for Mongol patronage . The last Timurid emir tried to gain iranian support to deal with the invading Uzbeks by appealing to shi'ism and even minted shia style coins but this angered his court in Central Asia so he dropped it. The Timurid realms would then be carved up by Ismail, Babur, and Shaybani. The Twelve Imams in particular appeared more in literature, invocations, etc. And finally we have travelogues from multiple time periods which note the shia populated regions in the middle east
