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: First Mongol invasion of Poland), and was not rebuilt until 1275. Later it was part of the territory of the Grand Duchy of Lithuania.