ENTogether with archaeological data, archaeobotanical results from plant macrofossils, pollen and 14C investigations reveal the existence of a permanent settlement in Vilnius Lower Castle during approximately the 6th century A.D. Evidence of the continuous cultivation of cereals, for example Fagopyrum esculentum and Secale cereale, and a clearly marked increase of the landscape cleared of woodland indicates an increase in human activity in the area during the later 13th and early 14th centuries A.D. In the middle of the 14th century human activity temporary declined, as shown by the recovery of woodland. During the second half of the 14th century, the expansion of the town of Vilnius resulted in woodland clearance and intensive agriculture. Intensive land use continued during the first half of the 15th century, which is known as a period of economic and cultural prosperity. Keywords: pollen, plant macrofossils, Middle ages, environmental changes, human activities. Fagopyrum esculentum. [From the publication]