In 1453, the fall of Constantinople, a bastion of Christianity in Asia Minor to Islamic Ottoman Empire; marked the end of the Eastern Roman Empire or Byzantine Empire, and severed European trade links by land with Asia. This massive blow to Christendom spurred the age of discovery as Europeans were seeking alternative routes east by sea along with the goal of forging alliances with pre-existing Christian nations. Along with pioneer Portuguese long-distance maritime travellers that reached the Malabar Coast in the late 15th century, came Portuguese missionaries who made contact with the St Thomas Christians in Kerala, which at that time were following Eastern Christian practices and under the jurisdiction of Church of the East. The missionaries sought to introduce the Latin liturgical rites among them and unify East Syriac Christians in India under the Holy See.