Prior to World War II, the city had undergone occupations by the French (1794–1815) and the British (1918–1926), and was part of Prussia beginning in 1815. Cologne was one of the most heavily bombed cities in Germany during World War II. The bombing reduced the population by 95%, mainly due to evacuation, and destroyed almost the entire millennia-old city center. The post-war rebuilding has resulted in a very mixed cityscape, restoring only major historic landmarks like city gates and churches (31 of them being Romanesque)