Despite several Paleolithic finds in the caves of the Balkan Mountains, the early inhabitants of the Bulgarian lands don't really enter the limelight of history until the sixth millennium BC, when the Balkans were a major centre of the so-called Neolithic Revolution . This came about when Stone Age hunters began to be replaced by a more settled, agricultural population - probably the result of a wave of migration from the Near East. This sudden flowering of organized culture is best observed at the recently excavated Neolithic village at Stara Zagora , famous for its decorated pottery, clay figurines and fertility symbols. By the fourth millennium BC mining and metallurgy took off in a big way: copper and gold objects found in the Chalcolithic necropolis near Varna show that the Balkan peoples were developing smelting techniques independently of the civilizations of the Near East.

Chalcolithic culture went into decline at the end of the fourth millennium BC, a process hastened by a worsening of the climate. Civilization in the Bulgarian lands was revitalized by the arrival of newcomers from Central Europe, bringing with them the metalworking techniques of the Bronze Age . By the end of the second millennium BC these migrant groups, together with the original tribes of the eastern Balkans, were coalescing into an ethnic and linguistic group subsequently known to history as the Thracians .