Constantina, daughter of Constantine, wife of Gallus Caesar, and patron of St. Agnes at Rome

Constantina, born in c. 320, was the eldest daughter of Constantine I. She was married twice, first in 335 to her cousin Hannibalianus, whose death in 337 left her widowed, and second in 351 to another cousin, Gallus Caesar. Between her marriages, she resided in Rome, founding the church of St. Agnes on the Via Nomentana, where she would be buried in an adjacent mausoleum after her death in 354. Constantina was an active political player in the early 350s. In 350, she intervened against the usurpation of Magnentius through proclaiming the magister militum Vetranio Caesar to her brother Constantius, and she exerted influence on her husband Gallus when the couple resided in Antioch from 351 to 354. Constantina was venerated as a saint in Rome in the 7th century.