Modern Greek (Greek: Νέα Ελληνικά or Νεοελληνική γλώσσα, "Neo-Hellenic", historically and colloquially, also known as Ρωμαίικα, "Romaic" or "Roman") refers to the varieties of the Greek language spoken in the modern era. The beginning of the "modern" period of the language is often symbolically assigned to the fall of the Byzantine Empire in 1453, even though that date marks no clear linguistic boundary and many characteristic modern features of the language had been present centuries earlier - from the fourth to the fifteenth century AD. During most of the period, the language existed in a situation of diglossia (due in part to the Dark Ages), with regional spoken dialects existing side by side with learned, archaic written forms. Most notably, during much of the 19th and 20th centuries, it was known in the competing varieties of popular Demotic and learned Katharevousa. Today, standard modern Greek, based on Demotic, is the official language of both Greece and Cyprus. Greek is spoken today by approximately 12-15 million people, mainly in Greece and Cyprus, but also by minority and immigrant communities in many other countries.