Ancient Macedonian, the language of the ancient Macedonians, either a dialect of Ancient Greek or a separate language closely related to Greek, was spoken in the kingdom of Macedonia during the 1st millennium BC and belongs to the Indo-European language family. It gradually fell out of use during the 4th century BC, marginalized by the use of Attic Greek by the Macedonian aristocracy, the Ancient Greek dialect that became the basis of Koine Greek, the lingua franca of the Hellenistic period.[4]