Carolyn, until 1918 and the abolition of the German monarchies following World War I, Hesse, or as it was also known at the time, Hesse-Darmstadt, was a Grand Duchy; that is, its reigning monarch was a Grand Duke.

Hamm and Mettenheim were both located in the former Hesse-Darmstadt, and to be precise, in the region of Hesse known as Rhenish Hesse (in German: Rheinhessen).

Following World War II, Rhenish Hesse (Rheinhessen) did not become part of today's postwar state of Hesse (in German: Hessen), but rather, it was made part of the newly created state of Rhineland-Palatinate (in German: Rheinland-Pfalz), of which the Rhenish Hessian city of Mainz became the capital. Thus, Mettenheim and Hamm are located in today's German state of Rhineland-Palatinate (Rheinland-Pfalz) in western Germany.

Mettenheim is today a town of about 1400 people, Hamm a town of about 2200 people. Mettenheim and Hamm are about 5 miles apart.

There is more than one Mettenheim in Germany, and there is more than one Hamm. The Mettenheim in question here is thus referred to in full as Mettenheim/Rheinhessen (Mettenheim/Rhenish Hesse), and the Hamm in question here is thus referred to in full as Hamm am Rhein (Hamm on the Rhine).

Robert