Cologne, located in the western part of Germany, is one of the oldest cities in the country. Its history dates back to the Roman Empire, where it was established as a colony and military base in the 1st century AD. The city played a crucial role in the spread of Christianity in Western Europe, with the construction of the Cologne Cathedral beginning in 1248. Cologne was heavily bombed during World War II, but many of its historical structures, including the cathedral, survived and have been restored.