The subject of this sketch is the Church of Sant’Agnese fuori le mura which stands on the Via Nomentana, north-east of the historic centre of Rome. Turner’s view looks south-east towards the church on the left with its Romanesque bell-tower. On the right is the circular Church of Santa Costanza, also known as the Mausoleum of Constantina, and in the centre are the ruined remains of the elliptical walls of an early basilica built by Constantine.1 The composition is identical to that copied by Turner from Select Views in Italy by John ‘Warwick’ Smith as ‘Temple of Bacchus’, see the Italian Guide Book sketchbook (see Tate D13966, Turner Bequest CLXXII 19, third from top right).
Further studies of this complex of buildings can be found on folios 35 and 62 verso (D16454 and D16432; Turner Bequest CXC 40 and 25a), whilst a view of the interior of Santa Costanza appears on folio 62 (D16431; Turner Bequest CXC 25). Like many drawings within this sketchbook, the composition has been executed over a washed grey background.
Compare the same view by an anonymous eighteenth century artist in Raymond Keaveney, Views of Rome from the Thomas Ashby Collection in the Vatican Library, exhibition catalogue, Smithsonian Institution, Washington 1988, no.64, pp.236–7, reproduced.