Kempen became a city in 1294 and the oldest seal dates from the same time. It shows besides a church two keys and the moon and star. The keys indicate the fact that the city belonged to the state of Köln, whose patron saint is St. Peter. The keys are the symbol of St. Peter. Moon and star probably symbolise the St. Mary. The present arms are based on a description from 1659. The keys and moon/star were now quarters in the new arms. The cross most likely is also the cross of the state of Köln.