The Cathedral of Saint Domnius in Split, Croatia, is widely considered the oldest Catholic cathedral in the world that remains in use in its original structure. It was originally constructed as the Mausoleum of Emperor Diocletian, built between 295 and 305 CE as part of the larger Diocletian's Palace complex. Following the decline of the Roman Empire, the structure was consecrated as a cathedral in the 7th century, dedicated to the city's patron saint, Saint Domnius.
The building is a unique architectural hybrid, blending its original Roman octagonal design with later medieval additions. The most prominent feature is the Romanesque bell tower, constructed in stages between the 12th and 16th centuries. The interior houses significant artistic treasures, including intricately carved wooden doors from the 13th century and a series of ornate altars that reflect the cathedral's long history as a center of religious life in Dalmatia.
Key Facts
- Materials
- Limestone, Marble, Brick
- Civilization
- Roman
- Accessibility
- Ground floor accessible, bell tower involves steep stairs
- Date(s)
- 295-305 CE
- Condition
- Well-preserved, active cathedral
- Original Function
- Mausoleum of Emperor Diocletian
- Key Figures
- Emperor Diocletian, Saint Domnius
Imperial Origins
3rd-4th century CEThe structure was built as the final resting place for Emperor Diocletian. It was designed as an octagonal mausoleum surrounded by a colonnade of 24 columns, featuring a domed interior decorated with mosaics.
Consecration and Conversion
7th century CEFollowing the abandonment of the palace by imperial authorities, the mausoleum was converted into a cathedral. The sarcophagus of Diocletian was removed, and the space was repurposed for Christian worship, dedicated to the martyrs Saint Domnius and Saint Anastasius.
Medieval Expansion
12th-16th centuryThe iconic bell tower was constructed over several centuries, beginning in the 12th century. During this period, the cathedral interior was also enriched with Romanesque choir stalls and the famous wooden doors carved by Andrija Buvina.
Modern Preservation
19th century-presentThe cathedral underwent extensive restoration in the late 19th century under the direction of Alois Hauser, who sought to remove later baroque additions to reveal the original Romanesque and Roman features. It remains a central component of the UNESCO-listed historic center of Split.