Interior of S. Maria Maggore in Rome

Interior of Santa Maria Maggiore in Rome, painted in 1750 and now at the Hermitage, demonstrates Panini's ability to treat ecclesiastical interiors with the same authority he brought to secular architectural subjects. Santa Maria Maggiore, one of Rome's four major basilicas, retains a largely intact early Christian nave with fifth-century mosaic decoration, making it one of the oldest and most historically significant church interiors in the city. By 1750 Panini had already painted Saint Peter's multiple times, and his treatment of the older, smaller Santa Maria Maggiore offered a contrasting study in the evolution of Christian architecture from early basilica to Baroque basilica. The Hermitage canvas, like the Sermon of St Paul from the same collection and year, reflects the strong Russian imperial interest in Panini's work during this period.

Santa Maria Maggiore's nave presented a different spatial challenge from Saint Peter's: narrower, lower, and more intimate, with ancient columns rather than Baroque pilasters defining the nave walls. Panini rendered the ancient marble columns with careful attention to their capital types, and the mosaic frieze above them is indicated with a warm golden tone that suggests the original fifth-century gold grounds.