The Collegiate Church of Saints Leonardo and Cassia is the main religious building in San Casciano dei Bagni and stands as one of the historical and spiritual symbols of this Tuscan spa town. Regarded as the successor to the ancient parish church of Balneo, documented as far back as the 11th century, the church has undergone centuries of architectural and institutional changes.

Over time, the collegiate church has changed its structure and ecclesiastical organisation on several occasions. Originally, it was governed by the so-called Pensioners of St William, linked to the nearby Guglielmite convent of Acerona. In 1618, it was elevated to the rank of Insigne Collegiata, with a Chapter comprising an archpriest and canons, appointed directly by the local community, which exercised the right of patronage.

Between the 17th and 18th centuries, the church reached the height of its splendour, aided by the presence of nobles, bishops and cardinals who frequented San Casciano for its renowned thermal treatments. Originally oriented along a west-east axis, the structure was subsequently rotated to its current south-north orientation, probably in the 16th century. The majestic stone bell tower, still a distinctive feature of the skyline today, was built in 1606.

Architecture and interiors

The façade retains elegant Gothic features: the large splayed portal, decorated with plant motifs, is surmounted by a rose window depicting Saint Leonard, whilst corner pilasters and a simple cornice complete the façade.

The interior comprises three wide naves covered by barrel vaults, creating a solemn and harmonious space. Four side altars line the naves, including those dedicated to Our Lady of Mount Carmel and the Holy Cross. Adjacent to the chancel are the Chapel of the Most Holy Rosary and the Chapel of the Sacred Heart.

The chancel, bordered by a travertine balustrade, houses the richly carved high altar, flanked by two large wooden angels. Dominating the wall is an altarpiece by Pietro di Francesco Orioli depicting the Coronation of the Virgin with Saints (c. 1490). Behind it lies the 17th-century wooden choir, whilst a gallery houses the organ.

The walls are adorned with numerous valuable paintings, including depictions of Saint Sebastian, Saint Michael the Archangel, the Baptism of Jesus and the Flight into Egypt. Of particular interest is also the finely carved travertine baptismal font, surmounted by a statue of Saint John the Baptist.

A symbol of faith and history

Today, the Collegiate Church of Saints Leonardo and Cassia remains the religious heart of San Casciano dei Bagni, a place where art, spirituality and history intertwine in a setting of great charm, closely linked to the area’s spa tradition.