MainzMainz, previously known in English as Mentz or Mayence, is the capital and largest city of Rhineland-Palatinate, Germany. Mainz is on the left bank of the Rhine, opposite the place where the Main joins the Rhine. Downstream of the confluence, the Rhine flows to the north-west, with Mainz on the left bank, and Wiesbaden, the capital of the neighbouring state Hesse, on the right bank. Mainz is an independent city with a population of 219,501 and forms part of the Frankfurt Rhine-Main Metropolitan Region.