This town is split into a Christian half and a Muslim half, with the Church of Saint George on one side and a mosque on the other. There are also Yezidis living here too, likely as IDPs.
Local legend says that Saint Thomas evangelised here. This may very well be true.
I halted the first day at Mankesh, a Chaldean Catholic village, situated in the midst of the most lovely mountain scenery, and abounding in valleys and heights on which the finest gifts of nature grow spontaneously. Stern (1848), p 115
Nowadays, there is a popular belief that India has a town also called Mangesh with an identical hermitage associated with him. This is not evidenced, however, and might be a corruption of the fact that there is a mountain in India named after Saint Thomas. This fact about Saint Thomas there could naturally have been exaggerated into the folklore about a Mangesh 'sister city' in India. This belief may have been enhanced by the similar-sounding Mangalore in India being an important seat of the Catholic population in that country.
Google BooksReverend H A Stern, 1848. Jewish Missionary Intelligence, Volume 14, Journal of the Reverend H A Stern.