The German town of Baden-Baden acquired its name officially in 1931 with a formal decision of the town's council. Before that, it was simply called Baden and was the capital of the Grand Duchy of Baden until 1918. Baden was a bathing spa in Roman times and was known as Aquae like Bath in England. Aquae in Latin and Bath in English have the same meaning as Baden in German. How did Baden end up with the weird tautology of being called Baden-Baden?