Form of Latin MARCUS used in several languages. Saint Mark was the author of the second gospel in the New Testament. Though the author's identity is not certain, some traditions hold him to be the same person as the John Mark who appears in the Book of Acts. He is the patron saint of Venice, where he is supposedly buried. Though in use during the Middle Ages, Mark was not common in the English-speaking world until the 19th century, when it began to be used alongside the classical form Marcus.
In the Celtic legend of Tristan and Isolde this was the name of a king of Cornwall. It was also borne by the American author Mark Twain (1835-1910), real name Samuel Clemens, the author of 'Tom Sawyer' and 'Huckleberry Finn'. He took his pen name from a call used by riverboat workers on the Mississippi River to indicate a depth of two fathoms. This is also the usual English spelling of the name of the 1st-century BC Roman triumvir Marcus Antonius (Mark Antony).