Complex sentence: It was formed in 1274 from the western part of the Duchy of Głogów and existed independently until 1304, then again from 1322 to 1394 and from 1413 to 1472.
Split into simpler sentences: It was formed in 1274 from the western part of the Duchy of Głogów. It existed independently until 1304, then again from 1322 to 1394 and from 1413 to 1472.