Modern Greek is the present vernacular language of Greece (also spoken in Cyprus), and is descended from Attic Greek.
Modern Greek (officially called "Demotic") evolved directly from Hellenistic Koine, an ancient Greek dialect founded after the conquests of Alexander the Great that was the vernacular language of the ancient Macedonian Empire. "Koine" had assimilated elements from many different Greek dialects (such as Doric and Aeolic) but its nucleus had always been Attic (the dialect of Athens). Koine had been spoken in several different forms in the region of Greece and the Greek speaking world during the entire Hellenistic, Roman and Byzantine periods, until the end of the middle ages when it took the shape of Demotic.
After Greece gained independence from the Ottoman Empire, the official Greek languages were Dhimotiki ("popular", a term similar to "vernacular") and Katharevousa ("purified"). Dhimotiki was the language of daily use, and the latter was an archaic form (closer to Attic), used for official documents, literature, newscasting and other formal purposes. In 1976 Katharevousa was totally obsoleted and replaced by Dhimotiki. During its long history the Greek language had assimilated some foreign vocabulary and loan words from various languages such as Latin, Italian, and Turkish, great part of which, was inevitably cleansed after its long-lasting co-existence with Katharevousa.