Until then, the Aromanians, as Eastern Orthodox Christians, were subsumed with other ethnic groups into the wider ethnoreligious group of the "Romans" (in Greek "Rhomaioi", after the Eastern Roman or Byzantine Empire), which in Ottoman times formed the distinct "Rum millet". The "Rum millet" was headed by the Greek-dominated Patriarchate of Constantinople, and the Greek language was used as a "lingua franca" among Balkan Orthodox Christians throughout the 17th–19th centuries. As a result, wealthy, urbanized Aromanians were culturally Hellenized and played a major role in the dissemination of Greek language and culture; indeed, the first book written in Aromanian was written in the Greek alphabet and aimed at spreading Greek among Aromanian-speakers.