Diocletian commissioned the Baths of Diocletian in Rome, completed in 306 CE.
The Baths of Diocletian were the largest imperial baths in ancient Rome. Construction began around 298 CE, during the reign of Diocletian, and the complex was completed in 306 under his successors. The baths stood on the northeastern side of Rome and could accommodate thousands of bathers at once.
Like other imperial bath complexes, they included bathing halls, exercise spaces, gardens, libraries, and areas for social activity. Their vast scale demonstrated the resources of the Roman state and the emperor’s ability to provide public amenities for the capital’s population.
The complex had a long afterlife. Parts of the surviving structure were incorporated into the Basilica of Santa Maria degli Angeli e dei Martiri, designed in part by Michelangelo, while other areas became the National Roman Museum’s Baths of Diocletian. The baths should not be confused with the earlier Baths of Caracalla, another enormous imperial bathing complex in Rome.