LOS ANGELES, CA (Catholic Online) - More amazing is the fact that Galla Placidia, a powerful Roman empress, was never buried there. Placidia, the daughter of Emperor Theodosius I and half-sister of Honorius became the powerful empress and the virtual ruler of the western world for 12 years between 425-37 as regent for her young son, Valentinian III.

Galla Placidia died in Rome on November 27, 450, and despite a long tradition to the contrary, it is unlikely she was ever buried in Ravenna. It's far more probable that she was buried in the Rotunda of St. Petronilla next to St. Peter's Basilica in Rome..

Scholarly opinion is that the Mausoleum of Galla Placidia was built as an oratory rather than a mausoleum. The mosaics of Galla Placidia have impressed millions of visitors over the centuries, including American songwriter Cole Porter. The story goes that while on his honeymoon in Ravenna in the 1920s, he wrote "Night and Day" while thinking of the starry sky of Galla Placidia.

The small brick chapel is extremely plain on the outside, concealing the glittering treasures inside. Shaped like a Greek cross measuring 40 feet by 30 feet, it has blind arches on its walls and a square tower over the crossing.

Entrance is through a small door on the north side. The plain north facade was once covered in marble; only a lintel with a carved frieze survives over the door.

The interior is lit by 14 windows, since 1908 filled with warm-hued alabaster to allow better viewing of the mosaics. The visitor's eye is immediately drawn upward, as the entire vault is covered in exceptionally beautiful and ancient mosaic work dating from about 430 AD. The walls are lined with marble panels.

The vault of the oratory features a lovely mosaic of a starry night sky. The stars, more than 800 of them are arranged in concentric circles around a golden Latin cross, with the symbols of the Four Evangelists on the spandrels. The arches of the side niches have similar golden patterns on a dark backdrop, featuring a variety of flowers and plants along with more stars.

Perhaps the most important mosaic in the Mausoleum of Galla Placidia is an early depiction of Christ as the Good Shepherd, located over the entrance on the north side. Instead of being shown as a typical countryman, this Good Shepherd has a large golden halo, wears a royal purple mantle over a golden tunic, and holds a tall cross. On either side of him are two groups of three sheep, who look peaceful and gaze up at their Shepherd. Christ tenderly touches the nose of one of them.