Kerala coast had been visited by mainly Arab and Jewish traders from the Middle East for centuries. Many of the traders would stay in the ports for many years and many of them took local wives. Mappilai muslims of Malabar trace their ancestry to arab admixture.
On a personal note, I cannot help noting the physiognomy of the people of coastal Kerala and the strong resemblance of the early christians to the Yemenite Jews and the Muslims to the Arabs of Mesopotamia.
