A couple more drawings have come my way of the Vatican Rotunda.
I have blogged before about this. It appears that a couple of circular tombs were built in the 3rd century AD in what had been the Circus of Gaius and Nero, just down the slope from where Constantine was to build the basilica of Old St Peter’s. The two tombs were incorporated into the structure as attached buildings, used as chapels. The western one was demolished when the new basilica was built, but the other remained until quite modern times, and was known as the Vatican rotunda.
The first image is from the Met Museum, and is a drawing by Antonio Tempesta of 1645. In fact it forms part of a map of Rome. Here it is:
This shows new St Peter’s, but without the colonnades. Instead the steps of Old St Peter’s are still there. The Vatican rotunda is in the middle of the south side of the basilica.
Now here’s the other, also from the Met Museum. Giovanni Battista Falda (Italian, 1643–1678). Veduta di Tutta la Basilica Vaticana (…), from Il Nuovo Teatro (…), 1665–1669:
Note the rotunda, in an unusual view, end-on, at the left-hand end of the colonnade.