Professor David Marshall has confirmed the attribution after inspection of the original. It probably dates from the 1650s when Codazzi frequently collaborated with Michelangelo Cerquozzi who added the staffage to his architectural landscapes.
Codazzi was fascinated by Rome's ancient monuments and he painted both capricci and topographical views incorporating many of the sites of the Forum. He painted a number of views of the Arch of Constantine and the Colosseum, sometimes with the Arch on the left of the composition, and on four occasions, including the present work, with the Arch framing the scene on the right: topographically correct when the viewpoint is taken from the west (see D.R. Marshall, Viviano and Niccolò Codazzi and the Baroque Architectural Fantasy, Rome, 1993, VC 97-8, VC 103-5; another version in the Boston Museum of Fine Arts VC105a, is regarded as a copy by Marshall). All these versions display minor variations in topography, architectural details and staffage.
The present work is closest to the larger picture at Lulworth (ibid., VC105, p. 220), which Marshall catalogues as 'Probably Viviano Codazzi and Michelangelo Cerquozzi', dating it to the late 1650s. He regards the present, unpublished, work as most probably the prime version from which the variants VC 105 and 105a derive. He has pointed out the presence of pentiments, such as the carved roundel on the Arch of Constantine that has been moved further to the right, which do not appear in the Lulworth picture. A number of subsidiary figures in the present composition were painted out in the larger picture. Furthermore, the architectural details in the present work are painted with a precision and finesse that bears comparison with his most accomplished work of the 1650s.