Indo-Greeks
This are the descendant of Ionia Greek people who married Indian people. Its believed that some remnants of the Indo-Greeks went from India at the time of the Migration period, to the Byzantine Empire and settled in Phrygia in Asia Minor, and called there Atsingani (Untochables), and became the Ancestors of the Roma people. The reason was the beginning of the caste system at 400 AD. At the time of the East-West Schism at 1054, they settled in Constantinople and married later Byzantine Greeks.