At least in two parts of India there were Christians in the pre-Cosmasian (ante circa 535
a.d. ) centuries of the Christian era.) In northwest India--rather in Afghanistan and Baluchistan and the neighbouring regions included in the kingdoms of Gondophares and "Mazdai" of the first half of the first century a.d. , where according to the Acts of Thomas (apocryphae) of about 200 a.d. Saint Thomas preached and was killed and buried--there were Christian bishoprics in 420, 424, 484, and 497 a.d. This is evidenced by specific mention in ancient Syrian documents brought to light at my instance by the late Dr. Muigana of John Rylands Library, Manchester. Christianity must have died out in that region sometime after 497 a.d.
-- Notebooks Category 15: The Orient > Chapter 6: Related Entries > # 102