Галла Плацидия
Aelia Galla Placidia, the likely patron of the building's construction was the daughter of Theodosius I and Galla. Raised by Serena, wife of Stilicho, she was made "nobillissima" in her youth and granted a palace by her father in Constantinople. She received an advanced education both secular and religious, as is evident from her letters. She married Athaulf, King of the Visigoths in 414 in Spain after moving to the West, though he soon died and she married the "patricius" Constantius (later Constantius III) in 417. Their children were Justa Grata Honoria and Valentinian III. Constantius III was elevated as co-emperor of the West in 421 by Honorius, who lacked an heir, and Galla Placidia was made "augusta"; Constantius died the same year and Galla Placidia fled to Constantinople. When Honorius died in 423, the "primicerius notariorum" Joannes succeeded as "augustus" in the West; thereafter Theodosius II, "augustus" in the East, moved to instal Galla Placidia's son Valentinian as emperor in the West instead, appointing him "caesar".