From the Latin name Marcus, borne by the Evangelist, author of the second gospel in the New Testament, and by several other early and medieval saints. In Arthurian legend, King Mark is the aged ruler of Cornwall to whom Isolde is brought as a bride by Tristan; his name was presumably of Celtic origin, perhaps derived from the element march ‘horse’. This was not a particularly common name in the Middle Ages but was in more frequent use by the end of the 16th century.
German: variant (also Förtner) or Americanized form of Pförtner, occupational name for the gatekeeper of a walled town or city, or the doorkeeper in a great house, castle, or monastery, Middle High German portenaere (from Latin porta ‘door’, ‘gate’). Compare English Porter.