The church is located in the heart of the medieval part of the city. Located in the lower area of the rocky hill on which the historic center of Campobasso develops, the religious building is adjacent to what used to be the main entrance, the homonymous Porta San Leonardo, which no longer exists, of the first settlement of Campobasso. Built in the 14th century, the facade of the church has Romanesque elements (single lancet window, rose window, cruciferous lamb, etc.) and a pointed portal, already characteristic of the later architectural style, the Gothic one. On the façade there is a bull, the symbol of King Bove, a legendary local figure linked to the construction of several Romanesque-style churches in the Molise area. From 1400 and for centuries it became the main church of the village of Campobasso. With the earthquake of 1456 there was the collapse of the bell tower, later never rebuilt. Its interior has a single nave. The church has a double flight of steps, rebuilt in 1900. The church overlooks the main square of the medieval center, enriching an already evocative architectural context. In 1587 the square was the place of peace between Crociati and Trinitari, the main congregations of the city in dispute for years over economic problems. Crociati were in fact linked to traditional agricultural activities while Trinitari had opened up to new economic systems. Longer the city remained divided, even bloody events took place and marriages were forbidden between the two sides but with the arrival of Fra Girolamo da Sorbo the peace process took place and the red and blue colors of the covenants were indissolubly linked.