member of a people of the Indo-European linguistic family living on the southeastern shores of the Baltic Sea. (The name Balt, coined in the 19th century, is derived from the sea; Aestii was the name given these peoples by the Roman historian Tacitus.) In addition to the Lithuanians and the Latvians (Letts), several groups now extinct were included: the Yotvingians (Jatvians, or Jatvingians; assimilated among the Lithuanians and Slavs in the 16th–17th century); the Prussians (Germanized in the 18th century); the Curonians (Cours, or Kurs; Latvianized in the 16th century); and the Semigallians (Zemgalians) and the Selonians (Selians, extinct in the 14th century). Estonians, inhabiting the region north of Latvia, are not Balts; they are members of the Finnic peoples.

The prehistoric origin of the Balts, as of other Indo-Europeans, is obscure, but they arrived in the vast area of the eastern Baltic and west-central Russia in the 3rd millennium BC, bringing with them knowledge of agriculture and cattle raising. Because of the inaccessibility of the western part of the area, which was bound in by sea, forest, and swamps, the Balts there—ancestors of Latvians and Lithuanians—maintained their individuality and paganism until the Middle Ages. Other Balts, however, were absorbed or displaced over the centuries; the eastern Baltic tribes, in particular, spread throughout Belarus and western Russia and were Slavicized after the northward expansion of the Slavs from the 7th to the 13th century AD.

In the 13th century the historical record of the Balts really begins, for it was then that the Teutonic Order and the Order of the Brothers of the Sword (Brothers of the Sword, Order of the) conquered the Balts inhabiting the areas of Estonia and Latvia and converted them forcibly to Christianity. In reaction to the Teutonic pressures, the Lithuanians consolidated themselves into a powerful state and, allied with the Poles, checked the German expansion; by 1386, when Lithuania officially adopted Christianity, it had become a great empire. After the union between Lithuania and Poland in 1569, however, the Lithuanian aristocracy became decidedly Polish in language and politics; cultural decline and territorial shrinkage began, and by 1795 all Baltic lands were under Russian rule, which persisted, except for a period of independence from 1918 to 1940, until 1991.

Since Christianization, the Lithuanians traditionally have been for the most part Roman Catholics, and the Latvians, since the Reformation, have been Lutherans. There are also small minorities of Greek Orthodox and other Protestants.

In the past, all Baltic peoples were mainly agriculturists and, especially among Latvians, stock farmers. Originally land was held by individual peasants, but, during the era of Soviet domination (1940–91), it was taken over by large state farms and collectives. At the same time, the proportion of the population working in agriculture and the position of agriculture in the economy steadily declined. There has been considerable industrial growth; engineering products, together with textiles, are of primary importance.

Both the Lithuanians and the Latvians, despite heavy Germanic and Slavic influences, have retained a rich tradition of folktales, songs, and poetry.