by the Polish since 1920, was returned, and the center of Lithuanian archaeology was transferred there.

Part of the U.S.S.R. (1940–1991)

World War II and the subsequent Soviet occupation of Lithuania interrupted any further archaeological work, and publications stopped. In 1940, the occupation government passed a law of cultural monuments protection, which had been prepared by an independent Lithuania and was really only a piece of political propaganda. Archaeology was centralized in order to achieve greater Soviet control. In 1941, the Academy of Sciences was created; in it, was an Institute of History and within that, a Department of Archaeology. During fighting in Lithuania, many parts of archaeological collections in local museums were destroyed. In 1944, to escape repression, Puzinas and his best student, Marija Gimbutienė (or Gimbutas, 1921–1994), went to western Europe. Gimbutienė completed her thesis in Germany in 1947, writing on Lithuanian grave-field data and separating it into cultural-chronological groups linked to some historic Baltic tribes. In Lithuania, the field archaeologist Pranas Baleniūnas (1900–1965) was arrested and imprisoned in northern Russia.

The main features of Lithuanian archaeology during the years the country was a Soviet socialist republic were the accumulation of archaeological sources and the investigation of the ethnic genesis of the Baltic tribes. In 1945, Lithuania had only four archaeologists left, and they had sole responsibility for re-creating and developing the discipline. The training of archaeologists never stopped, testimony to the work of Pranas Kulikauskas (b. 1913) and Regina Kulikauskienė (b. 1916). Marxism was compulsory, and its impact on Lithuanian archaeology directed research into areas of socioeconomic formation, productive forces, and relations to production. The Russian language was used, and the works of former investigators were ignored. The center for archaeology in Lithuania became the Institute of History, which issued the permits for excavations. Archaeology at Vilnius University consisted only of producing students.

Archaeological surveys and excavations of grave fields began in 1948, and before long, excavations became large and rapid—however, there were no journals in which to publish archaeological articles in the first postwar decade in Lithuania. In 1949, P. Kulikauskas finished his thesis on a grave field at Kurmaic˘iai in western Lithuania. At the beginning of Soviet rule, archaeologists copied prewar work but included the necessary Marxist changes. This work was narrow and purely historical in treatment, written according to preconceived social evolutionary schemes created by the Communist Party, and there was only one way to investigate and publish results. The highest achievement of this Stalinist style of Marxism in archaeology was the preliminary edition of the History of Lithuanian SSSR (Lietuvos TSR istorija 1953), which divided prehistory into the stages of development of primitive society.

After the death of Joseph Stalin in 1953, the Soviet states started to become more liberal, and so did archaeology. During this time, new humanitarian directions were created, and archaeological investigations were included in economic development projects. A new postwar generation of archaeologists started to work. Excavations took place at new building sites and large infrastructure building projects, such as the building of the Kaunas water reservoir in 1953–1957, excavations at Castle Trakai in 1951–1962, and work on the Vilnius lower castle in 1955–1961, which led to the adaptation of some of these buildings as museums. However, the law for the protection of cultural monuments was often ignored at the time, and many archaeological sites were destroyed. Still, new kinds of archaeological monuments, such as Stone Age settlements, were excavated. The liberalization of archaeology spread to the analysis of archaeological material using traditional chronological-typological methods, more choice in the direction of investigations, and the creation of larger archaeological generalizations, which could include the material of former investigators.

The first books on Lithuanian archaeology since World War II were published, including those dealing with archaeological finds, hill-forts