sentences:  Oefte was merged from Heiligenhaus into Kettwig in April 1936.On January 1, 1975, the district reform in the state of North Rhine-Westphalia became effective and Kettwig was separated from the Düsseldorf-Mettmann district (which was renamed to Mettmann), and merged into the city of Essen.The westernmost part of Kettwig, Mintard, merged into Mülheim an der Ruhr.