This is a German locational surname. Recorded in many forms including Maintz, Mainz, Mainsler, Maintsler, Mainzler, Mensler, Mentzel, Mentzler, and Menzler, however spelt it describes a man from the city of Mainz. The word means 'swamp' in pre7th century Northern German, as did the cognate mentz. In the Middle Ages Germany was divided into many states and small principalities, and between them they spoke twelve different dialects whch were effectively separate langauages and known as such. The languages were so different that a person from say Hamburg in the north, was unable to communicate with a Bavarian in the south. Regional differences still exist but only as dialects, although what is now Dutch could be said to be a survivor of an ancient German language. Furthermore locational surnames were from names. That is to say names given to people after they left their original homes to move somewhere else. The different languages and erratic spelling, soon created many variant forms. In this case early examples of the surname recording include those of Syfridus Mentzere of Weiterstadt in 1321, and Hans Mentsch of Effringer in 1401.