Between 1459 and 1462, Pope Pius II Piccolomini commissioned architect Bernardo Rossellino to build the cathedral of Santa Maria Assunta as the centerpiece of Pienza's urban transformation. Replacing a smaller Romanesque church oriented east to west, the cathedral was built on an unusual north-south axis to form Piazza Pio II. To create room for the trapezoidal square, Rossellino pushed the building as far south as possible, positioning the apse and transept directly over the steep hill slope.
What to see
Designed by Rossellino under the influence of Leon Battista Alberti, the travertine facade features four pilasters and a horizontal moulding separating the lower three portals from three upper arches resting on columns. Niches and a central oculus ornament the upper tier, crowned by a pediment with the papal coat of arms of Pius II. Outside, the apse is framed by tall Gothic windows, and the bell tower—restored in 1570 after a 1545 earthquake—houses four bells, including a large bell cast in Cortona in 1400 and three cast in the 20th century by Luigi Magni.
The interior adopts the German Hallenkirche layout observed by Pius II on his travels, featuring three naves of equal height under cross vaults, separated by piers with engaged columns and carved capitals. The apse contains three chapels illuminated by Gothic stained glass windows. The cathedral houses paintings commissioned by Pius II and two pipe organs: a primary organ built by Enrico Giustozzi in the 1970s and expanded by Paolo Ciabatti in 2024 to 42 stops and roughly 2,010 pipes, alongside a 20th-century Walcker positive choir organ.
Visiting
Recognized as an Italian national monument, the building serves as a co-cathedral for the Diocese of Montepulciano-Chiusi-Pienza. The steep terrain beneath the apse caused structural subsidence from the time of construction, prompting major underpinning works between 1911 and 1934 that uncovered the foundations of the earlier medieval church.
Our editors' tip
Step inside to observe how the high Gothic windows flood the three naves with light, offering a clear demonstration of how Rossellino merged Tuscan Renaissance architecture with northern European spatial design.