Licinia Eudoxia (Greek: Λικινία, 422 – c. 493) was a Roman Empress, daughter of Eastern Roman Emperor Theodosius II. In early childhood she was placed in a political marriage with the Western Roman Emperor Valentinian III. Following the assassination of Valentinian, the usurper Petronius Maximus compelled Eudoxia to marry him. Captured during the sack of Rome, which she was claimed to have helped instigate, Eudoxia spent seven years as a captive of the Vandal Kingdom before being ransomed by the imperial court at Constantinople.
Family
Eudoxia was born in 422, the daughter of Theodosius II, Eastern Roman Emperor and his consort Aelia Eudocia, a woman of Athenian origin. Her only known siblings, Flacilla and possibly Arcadius, predeceased their parents. Their paternal grandparents were Arcadius and Aelia Eudoxia. Their maternal grandfather was Leontius, a sophist from Athens.
The identity of her maternal grandfather was first given by Socrates of Constantinople. John Malalas later gave a more detailed account of her mother Eudocia's history. The identity of Eudoxia's maternal grandmother is not recorded.
First marriage
thumb|300px|Solidus minted in Thessalonica to celebrate the marriage of [[Valentinian III to Licinia Eudoxia. The bride's father, Theodosius II, stands between them on the reverse.]]
In 424, Eudoxia was betrothed to Valentinian III, her first cousin, once removed. The year of their betrothal was recorded by Marcellinus Comes. At the time of their betrothal, Valentinian was approximately four years old, Eudoxia only two. Galla Placidia was Valentinian III's mother and a younger, paternal half-sister of Arcadius. Valentinian III was at the time being prepared to claim the throne of the Western Roman Empire, which was held by Joannes. The latter was not a member of the Theodosian dynasty and thus regarded a usurper by the Eastern court. Within 424, Valentinian was proclaimed a Caesar in the Eastern court. The following year, Joannes was defeated and executed. Valentinian replaced him as Augustus of the West. In 439, Eudoxia was granted the title of Augusta, with the birth of their first daughter Eudocia. They also had a second daughter, Placidia. The births and eventual fates of the two daughters were recorded by Priscus, Procopius, John Malalas and the Chronicon Paschale. the assassination had been arranged by the wealthy senator Petronius Maximus.
Second marriage
thumb|Gold medallion of Eudoxia
Valentinian had no male descendants and had never designated an heir. Several candidates claimed the throne, with Eudoxia supporting Majorian. John of Antioch reports that Petronius Maximus, the highest-ranking of all Roman senators, secured the position of emperor by buying the loyalties of palace officials and the local military. Eudoxia was forced to marry him or face execution. Their marriage secured the connection of Maximus to the Theodosian dynasty. Prosper of Aquitaine reports that Maximus befriended the murderers of Valentinian III instead of punishing them. Both Prosper and Victor of Tonnena place the marriage of Eudoxia to Maximus only days following the death of her first husband, commenting with disapproval that the empress was not given a period to grieve for Valentinian.