The "AD" monogram thatAlbrecht Dürer used as a signature
Monograms were first used oncoins from as early as 350 BC. The earliest known examples are of the names of Greek cities which issued the coins, often the first two letters of the city's name. For example, the monogram ofAchaea consisted of the lettersalpha (Α) andchi (Χ) joined together.[1]
