Complex sentence: Oldenburg (Low German: "Ollnborg") is an independent city in Lower Saxony, Germany, during the period when was part of the French Empire it was call "Le Vieux-Bourg", in French.
Split into simpler sentences: Oldenburg (Low German: "Ollnborg") is an independent city in Lower Saxony, Germany. During the period when it was part of the French Empire it was called "Le Vieux-Bourg" in French.