The works for the realisation of the complex nowadays known as the Markets of Traiano, started, according to the dating reported on some tile cachets, presumably between 94 and 95 after Christ, during the empire of Domiziano.

The entire complex, that includes six levels one above the other, is laying on the hills of the Quirinale and is made of a ensemble of shops and environments with institutional functions such as the rooms allotted to the "procurator Fori Divi Traiani". At the centre, around the large rectangular room, covered by six vaults, are opened numerous commercial environments organised with a functional grid of streets; the complex of the buildings results to be a large market to which is added between the 12th and the 13th century the Tower of the Militias, afterwards covered on two thirds of its highness by the actual tile coatings.