The turbulent history of Paris, which since its founding in 300 BC has endured Roman conquest and attacks by the English and the Vikings. The city's fortunes were transformed by Napoleon, who embarked on ambitious projects to improve public health, and commissioned one of the world's most famous landmarks, the Arc de Triomphe, for his imperial capital. Developments have contributed to a city so magnificent the Nazi officer in charge of the World War Two occupation refused to obey orders to destroy it.