Pereiaslav is a historical town in Boryspil Raion, Kyiv Oblast, central Ukraine. It is located near the confluence of the Alta and Trubizh river…Pereiaslav is a historical town in Boryspil Raion, Kyiv Oblast, central Ukraine. It is located near the confluence of the Alta and Trubizh rivers some 95 km southeast of the capital Kyiv. It was one of the key regional centers of power during the medieval period and served as the capital of a principality. Pereiaslav hosts the administration of Pereiaslav urban hromada, one of the hromadas of Ukraine. Its population is approximately 26,273.