city, North Rhine-Westphalia Land (state), northwestern Germany. It lies along the Lippe and Ahse rivers and the Lippe-Seiten Canal, at the eastern edge of the Ruhr industrial region. Founded in 1226 as the capital of the county of Mark, it was a prosperous member of the Hanseatic League until the wars of the 17th and 18th centuries led to its decline. Hamm was revitalized by the Industrial Revolution in the 19th century.
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