One of Canaletto’s most important patrons was Joseph Smith, a British citizen who spent almost his entire life in Venice and was a passionate collector of paintings and drawings. Canaletto was one of his favorite artists and he eventually owned a large number of his works, all of which he eventually sold to King George III. In the early 1740s, Smith commissioned Canaletto to create a series of five paintings of Roman monuments. It is uncertain whether Canaletto journeyed to Rome for these works, or if he used sketches he had made in 1719-1720 when he was there with his father. Smith also had an extensive collection of prints of Roman views by earlier artists, so Canaletto may have used those as inspiration, as well. In his painting called Rome: the Arch of Constantine of 1742 (fig. 11), he depicts the north face famous monument, but places the viewer to the south of the arch. The church of San Pietro and the Colosseum are both visible through the arch. A cluster of figures makes up the foreground, which perhaps could represent students on their Grand Tour. In the foreground to the left is a figure that could represent Canaletto himself. This figure, an artist, is shown with a ruler and book, and could either be drawing or writing. The fact that Canaletto chose to sign and date this work on the piece of stone next to the artist and shaped the letters like the ancient inscription on the Roman arch suggests that he was asserting himself as an master whose works would last through time in the same way as the monuments of ancient Rome had survived.
Another painting made for Smith, Rome: Ruins of the Forum, Looking towards the Capitol of 1742 (fig. 12), represents the site of the forum, the political center of ancient Rome. More Grand Tourists occupy the space and they all appear to be admiring the newly excavated and imposing structures of the remains of the temple of Castor and Pollox. The columns direct the viewer’s attention upward above all the other buildings. The Temple of Saturn and the Palazzo Senatorio are also featured in this work, adding to the upward thrust of the composition. Although all of the historical sites are accurately represented, Canaletto made some additions of his own. Some of the houses off to the left are entirely made up, as comparison with contemporary views of the forum show, and the chimneys that adorn their roofs seem to be Venetian instead of Roman. It is as if Canaletto were turning the tops of the houses into horizontal lines that would balance out the strong verticalities of the other elements in this painting. This piece is unique because Canaletto combines the two worlds of Rome and Venice into one, calculated composition. This may be one of the first examples of a capriccio by Canaletto, meaning that he began not only to play with proportion and space, but he also blended architecture of different cities into one work. He signed and dated this work in the same way that he did in Rome: the Arch of Constantine (fig. 11).