The remains of the fourth-century Basilica of Constantine and Maxentius stand at the eastern end of the Roman Forum. This vast building, sometimes erroneously called the Temple of Peace, was once used for business and judiciary affairs. The edifice was the largest in the Forum and Turner’s sketch captures the scale of the surviving barrel vaults with their coffered ceilings. The circular shaped object with the architectural detailing on the ground in the bottom left-hand corner is a large section of collapsed ceiling masonry which can still be found in the same position today. On the far right is the campanile of the Church of Santa Francesca Romana.
The Basilica appears in a number of Turner’s sketchbook drawings, see folios 59 verso, 60, 60 verso, 61 and 61 verso (D16262–D16266; Turner Bequest 58a–60a) and Albano, Nemi, Rome sketchbook (Tate D15394; Turner Bequest CLXXXII 51a). It also dominates the right-hand side of Turner’s large oil painting, Forum Romanum, for Mr Soane’s Museum exhibited 1826 (Tate N00504).1
Martin Butlin and Evelyn Joll, The Paintings of J.M.W. Turner, revised ed., New Haven and London 1984, no.233.