The Regierungsbezirk (English: Government District) is a subdivision in 4 of the 16 federal states in Germany. It is governed by a Bezirksregierung (English: District Government) and led by a Regierungspräsident (English: Government President). The Regierungsbezirke do not pass any legislation. They are mostly concerned with administrative decisions on a regional level for the Districts covered.
Read more about Regierungsbezirk: History, Regierungsbezirke By State, Former States With Regierungsbezirke