The arrival of Islam in Sogdiana resulted in an immediate decline in written transmission of other major religions, and they were gone by approximately the year 1000 CE. Even the Pamirs, always a relative backwater, were Muslim by the middle of the medieval era. Of course Islam in the region, just like the world religions preceding them, was mixed with age-old pagan beliefs or laxly observant, but in terms of politics and society, Islam of some form certainly became the dominant religion early, and that was due to the violent overthrow of the preceding regime by Qutaya b. Muslim al-Bāhilī and the installment of one that chose Islam as an official religion.
Yet neighboring Nuristan (19th), Kohistan (18th), and Kashmir (17th) didn't fully islamize until the 17th-19th century - 7-10 centuries after Islam arrived in those regions.
> they were gone by approximately the year 1000 CE
Absolutely not.
Nestorian Christianity and Buddhism remained common in inner Asia until the 13th century with the Mongol invasions.
Depending on where you draw the line for Central Asia, non-Muslim religions remained significantly practiced in Central Asia well beyond that era as well.
At one point, the Tibetan empire even controlled Kabul during that era, and the Turk Shahis remained Buddhist or Hindu (depending on the leader) well beyond that era.
Even the leader of the Ghurid dynasty (Muhammad ibn Suri) was a Buddhist or Hindu Turk despite using a Muslim name.
> Nestorian Christianity and Buddhism remained common in inner Asia until the 13th century with the Mongol invasions.
I was talking about Sogdiana, not other regions of Central Asia, and 1000 CE is a standard cutoff date in scholarship for the end of the other world religions there.
