The Balts once inhabited a large portion of eastern Europe, and as a result, soon after their formation they began differentiating into separate tribes. Herodotus, the founder of the study of history, made note of the Neuri people who lived to the west of the Mordvians and north of the "Scythian farmers" and their neighbors the Boudinoi. Tacitus, a Roman historian of the 1st century, recorded the existence of the hardworking Aestiorum Gentes farmers and amber gatherers.
Many later historical sources mentioned separate Baltic tribes. These included Scandinavian sagas, various war and march chronicles, the memoirs of missionaries, letters and so forth. Through these records we know how the Balts fought and traded, how they worked the earth and what gods they worshipped. The Baltic tribes consolidated into their final forms in approximately the 5th and 6th centuries. The Lithuanian and Aukstaiciai people drew closer to one another as Slavic invasions from the east stimulated the formation of a central Lithuanian state. From these tribes and others including the zemaiciai, and a portion of the Kurshes, Semigallians and Sellians arose the Lithuanian nation. The Latvian people arose from neighboring tribes to the north. These are the only two Baltic cultures that have survived until today. The Prussian tribes were destroyed in battles with crusaders, whose descendants later named their country Prussia. Some of the original Prussians and Yotvings fled to Lithuania. Baltic peoples living in the eastern expanses of Europe were assimilated into Slavic culture. Their legacy included only a few tribe names as well as many archaeological artifacts, hydronyms and cultural substrata.
"LITHUANIAN ROOTS", Edited by Rytis Ambrazevicius