波列斯瓦夫一世
The Polish territorial sovereignty was acknowledged to Duke Bolesław I Chrobry by Emperor Otto III at the Congress of Gniezno in 1000. Nevertheless, Bolesław laid claims to the lands west of the Bóbr, which he temporarily acquired by the 1018 Treaty of Bautzen. After Emperor Conrad II had reconquered the territory until 1031, the "status quo" was restored.