Katharinenkirche und Mausoleum, Graz, Mannerist church and mausoleum in Innere Stadt, Graz, Austria

The Katharinenkirche and Mausoleum of Emperor Ferdinand II in Graz joins a cross-shaped church to an oval burial chapel with the first oval dome built outside Italy. The west facade has a curved pediment, four columns, and a sandstone sculpture of St. Catherine flanked by angels; painted copper panels show scenes from her life. Two green domes with lanterns rise above, one topped by a cross, the other by an imperial eagle holding orb and sword.

The mausoleum was built in the 17th century as a burial place for Ferdinand II, an important Habsburg ruler. This period shaped how Austrian religious buildings incorporated royal commemoration.

The church is dedicated to Saint Catherine of Alexandria, patroness of the Jesuit University of Graz founded in 1585. Its west facade shows a life-size sandstone figure of Catherine flanked by angels, with painted copper panels depicting scenes from her life. The figures of Porphyrius and Faustina, converted by her, carry a Counter-Reformation message.

The complex stands next to Graz Cathedral in the Innere Stadt. The southwestern stairway was added later, after the site was widened, to open up a clearer view of both facades; from its head the double-arched portal and the three roof statues are seen frontally. The interior was restored between 2002 and 2003, and further work on the 17th-century roof truss was planned for 2025.

The oval dome of the burial chapel was the first of its kind built outside Italy. Its mathematical form rests on the ellipse, whose construction Johannes Kepler worked out while teaching mathematics at Graz's Protestant Stiftsschule between 1594 and 1600.