List of Augustae
Augusta (Classical Latin: [au̯ˈɡʊsta]; plural Augustae; Greek: αὐγούστα) was a Roman imperial honorific title given to empresses and honoured women of the imperial families. It was the feminine form of Augustus. In the third century, Augustae could also receive the titles of Mater Senatus ("Mother of the Senate") and Mater Castrorum ("Mother of the Camp") and Mater Patriae ("Mother of the Fatherland").
The title implied the greatest prestige. Augustae could issue their own coinage, wear imperial regalia, and rule their own courts.
Wife of Claudius, Agrippina was the first wife of the emperor in Roman history to receive the throne of Augusta, a position she held for the rest of her life, ruling with her husband and son.
In the third century, Julia Domna was the first empress to receive the title combination "Pia Felix Augusta" after the death of her husband Septimius Severus, which may have implied greater powers being vested in her than what was usual for a Roman empress mother and in this innumerable official position and honor, she accompanied his son on an extensive military campaign and provincial tour.