The Medieval Dog

Strange as it may seem, the symbol @, which Russians call a "dog", appeared long before the internet: it was invented back in the Middle Ages.

To economise precious parchment and the copyists' time, monks replaced the frequently occurring Latin preposition "ad" with a ligature of intertwined letters "a" and "d".

With the invention of printing, this ligature survived and came into wide use in business documents, spreading into trade and becoming the sign for the "arroba", an old unit of weight. By this time the vertical stroke of the d had shrunk to a line extending from the a.

On the keyboards of the first American typewriters the sign appeared in 1885 and sat on the "a" key, since accountants made such active use of it.

And in 1971 Ray Tomlinson, searching for a separator for email addresses, chose precisely this medieval sign.