Chiesa di San Giovanni de Duce e Sostruzioni Sillane

The Church of San Giovanni de Duce stands on Piazza Dante in Anagni, over Roman retaining works known as the Sostruzioni Sillane. Its eighteenth-century interior and the Republican-era masonry below bring together two distinct periods in the city's history.

Why it matters

The square occupies the site of the forum of ancient Anagnia, where the decumanus and the route known as Via Bagno converged. The church's documented history reaches back to the thirteenth century, and its present form dates largely to an eighteenth-century rebuilding by the Regolari Minori, also known as the Caracciolini. Beneath the piazza, Roman substructures terrace the hillside with large retaining arches.

What to notice

The church has an eighteenth-century façade with a pedimented portal, niches and statues of its titular saints. Inside, the Greek-cross plan is covered by a dome carried on four arches. The altarpiece by Giovanni Battista Gaulli, known as Baciccia, depicts Saint Francesco Caracciolo, founder of the order that took possession of the church in 1725. In Via Bagno, the Sostruzioni Sillane include four round-headed arches, with outer faces in opus quadratum and inner construction in opus incertum.

Context and history

Tradition places a temple of Saturn on the site, while the church itself is documented from the thirteenth century. Pope Benedict XIII granted it to the Caracciolini in 1725; the rebuilt church was consecrated in 1745 to Saint John the Evangelist and Saint Benedict. Later restoration followed in 1888, and wartime bombing caused further damage. The Roman substructures below the square belong to the early first century BC, when retaining works were built to level this part of the forum.