The partnership of Jean Covens and Corneille Mortier was founded in 1721 by the two brothers-in-law. It was built on the business of Corneille’s father Pierre Mortier who began in 1685. The firm through their descendants would survive until 1866. This fine large scale map depicts the course of the River Rhine in Germany from Bonn in the north to Worms in the south. The Moselle River is also featured depicting at their confluence Koblenz. Further upriver the city of Mainz marks the location of the River Main leading to the important city of Frankfurt. Koeman II pp. 45-86.