Theodosian dynasty in the context of "Valentinian III"

The Leonid dynasty or Thracian dynasty produced six Byzantine emperors during Late Antiquity, reigning over the Byzantine Empire from 457 to 518. The dynasty's patriarch was Leo I, who was made Byzantine emperor in 457. Leo's daughter Ariadne became empress and mother to an emperor, and her two husbands were themselves each made emperor in turn. Another relative whose name does not survive of Leo I or his wife Verina married the future augustus Julius Nepos (r. 474–480), the last emperor in the Western Roman Empire. The dynasty of Leo succeeded the preceding Valentinianic dynasty (r. 364–455) and Theodosian dynasty (r. 379–457) whose family trees were conjoined and ruled concurrently. Besides Julius Nepos, who administered no more than a rump state the Roman province of Dalmatia in the western empire during the fall of the west, the dynasty's emperors governed the Byzantine Empire (east).

Leo's eldest daughter Ariadne married Zeno, and their son, Leo II was proclaimed augustus and succeeded his grandfather Leo as an infant, appointing Zeno co-augustus. Leo's younger daughter, Leontia, married first the caesar Patricius, son of the magister militum Aspar, and then Marcianus, son of the augustus Anthemius (r. 467–472). When Leo II died in the year of his grandfather's death, Zeno remained augustus in the Byzantine Empire.

Count Theodosius (Latin: Theodosius comes; died 376), Flavius Theodosius or Theodosius the Elder (Latin: Theodosius major), was a senior military officer serving Valentinian I (r. 364–375) and the Western Roman Empire during Late Antiquity. Under his command the Roman army defeated numerous threats, incursions, and usurpations. Theodosius was patriarch of the imperial Theodosian dynasty (r. 379–457) and father of the emperor Theodosius the Great (r. 379–395).

Appointed comes rei militaris per Britannias (commander of mobile military forces for the Diocese of the Britains) by Valentinian, Theodosius put down the Great Conspiracy (367–368) and the usurpation of Valentinus. After restoring order in Britain he returned to continental Europe and fought against the Alemanni; as Valentinian's magister equitum (Master of Horse) he successfully invaded Alemannic territory (371 or 370). In 372 Theodosius led a successful campaign against the Sarmatians. Within the same year Firmus, a Mauritanian prince, rebelled against Roman rule with the help of African tribes like the Abanni and Caprarienses. Theodosius was sent to Africa and in two hard-fought campaigns (373–374) put down the insurrection. In 376, after the death of emperor Valentinian, he was arrested and executed, presumably as he was seen as a threat to the new western emperors Gratian and Valentinian II.

The Valentinian dynasty, commonly known as the Valentinianic dynasty, was a ruling house of five generations of dynasts, including five Roman emperors during late antiquity, lasting nearly a hundred years from the mid fourth to the mid fifth century. They succeeded the Constantinian dynasty (r. 306–363) and reigned over the Roman Empire from 364 to 392 and from 425 to 455, with an interregnum (392–425), during which the Theodosian dynasty ruled and eventually succeeded them. The Theodosians, who intermarried into the Valentinian house, ruled concurrently in the east after 379.

The Valentinian dynasty's patriarch was Gratianus Funarius, whose sons Valentinian I and Valens were both made Roman emperors in 364. Valentinian I's two sons, Gratian and Valentinian II both became emperors. Valentinian I's daughter Galla married Theodosius the Great, the emperor of the eastern empire, who with his descendants formed the Theodosian dynasty (r. 379–457). In turn, their daughter, Galla Placidia married a later emperor, Constantius III (r. 421–421). Their son, Valentinian III (r. 425–455), who ruled in the west, was the last emperor of the dynasty, whose death marked the end of dynasties in the western empire. During the interregnum, Theodosius' son Honorius ruled in the west, and concurrently with Constantius III in 421. The dynasty has been labelled as Pannonian, based on the family origin in Pannonia Secunda in the western Balkans.

Procopius Anthemius (Ancient Greek: Προκόπιος Ανθέμιος, romanized: Prokópios Anthémios; died 11 July 472) was the Western Roman emperor from 467 to 472. Born in the Eastern Roman Empire, Anthemius quickly worked his way up the ranks. He married into the Theodosian dynasty through Marcia Euphemia, daughter of Eastern emperor Marcian. He soon received a significant number of promotions to various posts, and was presumed to be Marcian's planned successor. However, Marcian's sudden death in 457, together with that of Western emperor Avitus, left the imperial succession in the hands of Aspar. He instead appointed Leo, a low-ranking officer, to the Eastern throne, probably out of fear that Anthemius would be too independent. Eventually, this same Leo designated Anthemius as Western emperor in 467, following a two-year interregnum that started in November 465.

Anthemius attempted to solve the two primary military challenges facing the remains of the Western Roman Empire: the resurgent Visigoths, under Euric, whose domain straddled the Pyrenees; and the unvanquished Vandals, under Geiseric, in undisputed control of North Africa. Anthemius's insistence on ruling independently placed him into direct conflict with the Gothic general Ricimer. Previously the real power behind the throne, Ricimer found that Anthemius's reign threatened his own interests. This eventually escalated into open warfare between the two, with the result that Anthemius lost not only his throne, but also his head, in 472.

Serena (died 409) was a member of the Theodosian dynasty as the niece of the emperor Theodosius I, as well as the wife of the military commander Stilicho.