Notre-Dame-de-la-Sède Cathedral, Romanesque cathedral in Saint-Lizier, France

Notre-Dame-de-la-Sède is a former cathedral in Saint-Lizier, built from the late 11th century in a simple Romanesque style with a single nave. Its south wall rests on the Late Roman town wall, giving the building a skewed plan. The nave, 21 metres long and 9 metres wide, is lit by six openings and flanked by three lateral chapels added in the 14th century. The interior preserves 19th-century paintings and Renaissance murals uncovered during restorations between 2003 and 2010.

Notre-Dame-de-la-Sède was built from the late 11th century as a simple single-nave Romanesque church on the heights of Saint-Lizier, its south wall resting on the Late Roman town wall, which gives the building its skewed plan. In the 12th century a Romanesque cloister and a vaulted chapter house were added; the vault was raised and three side chapels built in the 14th century. Around 1990 traces of old paint were found while woodwork was being restored, and campaigns in 2003-2004 and 2009-2010 uncovered a monumental set of Renaissance murals commissioned by Bishop Jean d'Aule (1475-1515).

The cathedral displays murals depicting the sons of Jacob and ancient Sibyls, with Latin inscriptions conveying messages about the arrival of the Savior. These images shape the interior space and tell of medieval religious beliefs.

The building is part of the Departmental Museum of the Bishops' Palace and can be visited with guided tours that explain the architecture and artistic works. Access is through the adjoining museum building, which also offers insights into the history of the place.

The south wall of the church abuts the Late Roman rampart of Saint-Lizier, which was already standing when the nave was built at the end of the 11th century. Because the builders followed that existing wall, the plan of the building is skewed rather than regular. The rampart was not found by excavation; it was reused in place.