The contemporary author Gallus Anonymus in his Gesta principum Polonorum, written between 1112 and 1118, mentioned several armed encounters with the Imperial forces led by King Henry V of Germany. After Bolesław had invaded the Bohemian territory of Duke Svatopluk, the German king in turn started a campaign to Poland and laid siege to the towns of Bytom Odrzański and Głogów, before he moved further down the Oder River and marched against Wrocław, though to no avail. The site is now part of the Psie Pole district of modern Wrocław.