The Lithuanians or Old Lithuanians (Latin: Letwini;Baranauskas, Tomas (2006). Aukštaitija XIII–XV amžiuje [Aukštaitija in the 13th–15th Centuries]. In (Eds.), Aukštaičių tapatumo paeiškos [Searches of Aukštaitian Identity] (in Lithuanian). Kaunas: Žiemgalos leidykla. .:33 Low German: Lettowen;Volkaitė-Kulikauskienė, Regina (1970). Lietuviai IX–XII amžiais [Lithuanians in the 9th–12th Centuries] (in Lithuanian). Vilnius: Mintis. p. 35. "„Die Lettowen al zu hant, die Sameyten sint genant.“ cf. LRCH 5445" Old East Slavic: Литъва, Литва;Zinkevičius, Zigmas (1987). Lietuvių kalbos istorija: iki pirmųjų raštų [The History of the Lithuanian Language: Before the First Written Works] (Vol. 2) (in Lithuanian). Vilnius: Mokslas. p. 11. Old Swedish: lättugha;Ljungar, Wilhelm (2022). Till gudz riddara han tha ouer foor. Warfare as Religious Experience in the Swedish Medieval Rhyme Chronicles 1320–1496 [PDF]. Historiska Institutionen Stockholms Universitet. pp. 54–55. modern Lithuanian: senlietuviaiGrigas, Romualdas (2017) . Senieji lietuviai ir krikščionybė: tapatybių konfrontacija [The Ancient Lithuanians and Christianity: The Confrontation of Identities]. In (Eds.), Liaudies kultūra [Folk Culture] (in Lithuanian, abstract available in English). Lithuanian National Culture Centre. (6): 7–15. p. 7. ISSN 2669-0403.) were one of the largest East Baltic tribes, inhabiting present-day Eastern Lithuania in the 5th–13th centuries."Baltų gentys. Arealas, laidosena, kostiumas" [Baltic Tribes. Areal, Burials, Clothing] (in Lithuanian). Baltų kelias. Retrieved on 5 February 2025. Following the Northern Crusades, the ancient Lithuanians began gradually assimilating other neighbouring Baltic tribes, becoming the primary progenitor group of modern Lithuanians.

History Origin and trade It is believed that ancient Lithuania initially covered around 80,000 km2 and was home to around 300,000 inhabitants, most of them living as farmers."Lietuva visuomenės valstybės susidarymo išvakarėse. Visuomenė" [Lithuania on the Eve of Societal State Formation. Society] (in Lithuanian). Istorija. Retrieved on 5 February 2025. Traditionally historians divide the area into six attested lands – Nalšia, Deltuva, Upytė, Lietuva, Neris and Deremela, with Lietuva (Lethowia):33 passing on its name to the entire country. There was a sevenfth land laying in between Neris, Merkinė and Neman rivers but no records of its name remain.Zabiela, Gintautas (2006). Aukštaitijos žemės [Lands of Aukštaitija]. In (Eds.), Aukštaičių tapatumo paeiškos [Searches of Aukštaitian Identity] (in Lithuanian). Kaunas: Žiemgalos leidykla. pp. 21–26. . Ancient Lithuania stretched from the middle reaches of Neman to the Southeast of Šventoji.

Because of the three archaeological cultures in Lithuania, some scholars divide the Lithuanian ethnos into three cultural groups – Samogitians (Western), Aukštaitians (Central) and Lithuanians (Eastern). Traditionally, the Samogitian tribe is included within the broader Lithuanian ethnos as suggested by historical accounts, dividing Lithuania into two parts – Austechia (Aukštaitija) and Samogitia (Žemaitija):1Misiūnas, Romuald J., Bater, James H. Prehistory to the 18th Century. Baltic states. Encyclopaedia Britannica. – but their origins are a subject of ongoing debate. Linguist Jūratė Sofija Laučiūtė argues that prior to their assimilation, ancient Samogitians were a different tribe from the Lithuanians, which is evinced by certain linguistic features not explainable by phonetics alone, such as the ending -ou <*-ou of masculine nouns in the genitive form (e.g. Samogitian velkou, Lithuanian vilkui, meaning () 'wolf'). Valdemaras Šimėnas suggests that both culturally and linguistically ancient Samogitians were closer to Curonians, Semigallians and Selonians than to the Lithuanians.Kavaliauskas, Antanas (1 January 2018). "Žemaičių kilmės problematika" [The Problematic Nature of Samogitian Origin] (in Lithuanian). Kalvotoji Žemaitija. Retrieved on 5 February 2025. The Samogitians formed a tribal union with the Lithuanians, which was an ongoing process starting in and culminating by the early 13th century. Its centre was in present-day south-eastern Lithuania.Gumuliauskas, Arūnas (2010) . Lietuva: nuo valstybės susikūrimo iki valstybės atkūrimo [Lithuania: From State Formation to State Restoration] (in Lithuanian). Vilnius: Debesija. p. 21. Samogitia also maintained its own distinct land confederation, capable of withstanding external military aggression as shown during the Battle of Saulė in 1236, yet over time it became increasingly dependent on Lithuania, as demonstrated by the Lithuanian campaign through its territory into Courland () or the Samogitian–Order alliance against the Lithuanians (1248), formed to resist their attempts at asserting control over northern Samogitia, by then the last part of the region not under their direct rule.Almonaitis, Vytenis (1998). Žemaitijos politinė padėtis 1380–1410 metais [The Political Situation of Samogitia in 1380–1410] (in Lithuanian). Vilnius: Vytautas Magnus University Publishing Centre. pp. 47–48. .

Lithuania proper consisted of two archaeological cultural areas – Central and Eastern – with the former never becoming a continuous ethnopolitical unit.:30 Though contested, based on the spread of cremation and West Baltic acculturation, it is believed that the Aukštaitians were a consequence of westward Lithuanian migration into a Samogitian heterogeneous cultural zone, driven by Slavic expansion.Girininkas, Algirdas, Lukoševičius, Olijardas (1997). Lietuvos priešistorė: materialinės ir dvasinės kultūros raida, genčių formavimasis [Lithuanian Prehistory: Development of Material and Spiritual Culture and Tribal Formation] (in Lithuanian). Vilnius: Agora. p. 153. . "Dalis tyrinėtojų mano, kad nebuvo atskiros aukštaičių genties. Teigiama, esą čia gyvenusius žemaičių protėvius sulietuvino iš rytų atėję lietuviai. [Some researchers believe that a distinct Aukštaitian tribe did not exist. It is claimed that the Samogitian ancestors living here were Lithuanized by the Lithuanians coming from the east.]"Volkaitė-Kulikauskienė, Regina (1987). Lietuvių etnogenezė [The Lithuanian Ethnogenesis] (in Lithuanian). pp. 155–156. Central Lithuanian culture existed in the 6th–12th centuries, reaching its prosperity in the 9th–11th centuries. Burial practices and ceramics indicate that Central Lithuania was affected by the West Baltic cultures and belonged to the zone of maritime influence. Recent archaeological research reveals that Vikings navigated the Neman River, engaging in trade with the local populations, whereas Kaunas emerged as a significant economic and political trading centre.Songaila, Gintaras (2015). Ar vakarų ir rytų baltai turi bendrą politinę istorija? [Do West and East Balts Share a Common Political History?]. In (Eds.), Vėluojanti istorija ar pavėlavę istorikai? [Late History or Late Historians?] (in Lithuanian). p. 17. ISSN 2029-9516. The Lithuanians were familiar with surrounding waterways around the Baltic Sea and the Curonian Lagoon, initially possessing fluvial watercraft.:12 By the early 13th century, Lithuanian ships ventured into the Baltic Sea and reached the shores of Gotland where they would trade goods such as amber, honey, beeswax, flax, hemp or ash – this lasted until 1229 when Pope Gregory IX restricted the rights of traders and banned the practice of selling goods to the heathens.Vaitiekūnas, Stasys (2009). Lithuanians: From Agrarian to Sea Nation? (Historical-Geographical Study). In (Eds.), The Problems of Development and International Cooperation in the Region of the Southern Baltic. Pelpin: Wydawnictwo Bernardinum. .:28 In the 12th–13th centuries, Eastern Lithuania witnessed notable social and economic development, fostering advancements in trade, artisanship and political stability. In contrast, the western Baltic regions experienced a decline, as indicated by the substantially greater number of archaeological monetary finds in Eastern Lithuania.Genys, Jonas (2008) . Stages in the Early Developement of the Lithuanian Town. In (Eds.), Archaeology and History of the Middle Ages (in English, German and French). Series Colloquia. Forlì: Abaco Edizioni. .

In the 4th–8th centuries, with the loss of Roman commerce and coins, Lithuania and other Baltic lands had no known currency and are believed to have been trading in kind.Jurgutis, Vladas (2010) . Pinigai [Money]. Vilnius: Mintis. p. 62. . As of the 8th century, silver dirhams were gradually introduced to the region by either neighbouring or Arabic merchants,Michelbertas, Mykolas (2006). Lietuvos pinigai [The Money of Lithuania]. Kaunas: Šviesa. p. 11. . possibly reaching Eastern Lithuania through the Daugava River and southern Rus'.Duksa, Zenonas (1981). Pinigai ir jų apyvarta [Money and Its Circulation]. In (Eds.), Lietuvių materialinė kultūra IX–XIII amžiuje [The Lithuanian Material Culture in the 9th–13th Centuries] (Vol. 2). Vilnius: Mokslas.:59 From the 10th century onward, forged and smelted silver alloys of Scandinavian origin were brought to Lithuania and used as currency or jewellery.:4 In the mid-12th century, once their production abroad has fallen out of favour, ancient Lithuanians began producing their own currency – long silver ingots with cut marks – commonly known as kapas or ilgasis.:105

Society and culture Archaeologist Laurynas Kurila believes that by the 5th century, the Lithuanians began adopting a war-based societal model found in military democracies.Kurila, Laurynas (2009). Socialinė organizacija Rytų Lietuvoje III–XII a. (laidojimo paminklų duomenimis): disertacija [Social Organisation in Eastern Lithuania in the 3rd–12th c. (Based on the Data of Burial Monuments): Dissertation] (in Lithuanian). Vilnius: Vilnius University. p. 138. The tribal society was governed following the customary law and was based on a hierarchical structure consisting of four divisions – a duke, soldiers, free peasants (laukininkai) and slaves (šeimynykščiai). By the 9th century, a chieftain gradually became known as kunigas. Commencing in the 12th century, each ruler began to govern a particular land through hereditary succession and adopting the title kunigaikštis."Kunigai" (in Lithuanian). Universal Lithuanian Encyclopedia.

In ancient Lithuanian culture, religious suicide was practised and likely common. The Lithuanians were known to engage in acts of honour suicide by sacrificing themselves to their gods or after defeat in battle.Beresnevičius, Gintaras (2004). Lietuvių religija ir mitologija [Lithuanian Religion and Mythology] (in Lithuanian). Vilnius: Tyto alba. pp. 110–111. . In addition, Lithuanian women would take their own lives following the loss of their husbands. The latter custom was attested by Henry of Latvia when 50 Lithuanian wives of the defeated warriors chose to hang themselves to reunite with them in the afterlife.:51–52 In a letter from Pope Honorius III written in 1218, it is said that the Lithuanians practice human sacrifice of war captives to their gods.Dundulienė, Pranė (1991). Lietuvių etnologija [Lithuanian Ethnology] (in Lithuanian). Vilnius: Mokslas. p. 206. .