Dom Luis is an iconic bridge, both because of the beautiful view it offers of the old part of the city and, above all, for the history behind the reason it was built. France and Portugal have not always had good relations. At the beginning of the 19th century, the British used Portugal's ports to do business with Brazil; sometimes, they collaborated with them to prepare for military operations against France. Napoleon the Great wanted to break the strong bond between Portugal and Britain, and, to do so, he resorted to violence. Napoleon invaded Lisbon with the help of the Spaniards with the aim of displacing the British and gaining the upper hand in Atlantic trade. The invasion "inaugurated" the Peninsular War (1807-1814) and changed the fate of Porto.