 Complete the following phrase:  The city was founded by the Slavs. As a town, Brest  Berestye in Kievan Rus  was first mentioned in the Primary Chronicle in 1019 when the Kievan Rus took the stronghold from the Poles. It is one of the oldest cities in Belarus. It was hotly contested between the Polish rulers kings, principal dukes and dukes of Masovia and Kievan Rus princes, laid waste by the Mongols in 1241 see: 