In the centuries after the advent of Islam in the 7th century in Arabia, religious doctrines against homosexuality were likely trafficked by Arab and Persian traders the Indian oceanic coastline, and later the Omani and Portuguese settlers along the coastline up until the 19th century. With the arrival of European missionaries and explorers into the interior in the mid-19th century, the anti-homosexual doctrine of Christianity began to be disseminated among the various ethnic groups in the region.