 In that case the chief mayor has also the duties and powers of a "Landrat".The term "Oberbürgermeister" is not used in the three city-states, where the mayors are simultaneously head of state governments, but "Regierender Bürgermeister" (Governing Mayor of Berlin), "Erster Bürgermeister" (First Mayor of the city-state of Hamburg) and "Präsident des Senats und Bürgermeister" (President of the Senate and Mayor of Bremen) are used.Mayors (δήμαρχοι, "dēmarchoi", sing.