Leo I (emperor) in the context of "Glycerius"

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.

Zeno (/ˈziːnoʊ/; Ancient Greek: Ζήνων, romanized: Zénōn; c. 425 – 9 April 491) was Eastern Roman emperor from 474 to 475 and again from 476 to 491. His reign was plagued by domestic revolts and religious dissension, but was more successful on the foreign front. He is credited with further stabilizing the Eastern empire, while the Western Roman Empire fell following the deposition of Romulus Augustulus.

Born in Isauria, Zeno was known as Tarasis before adopting his Greek name and becoming an ally of Emperor Leo I, who saw the Isaurian general as an important counterweight against the Germanic leader Aspar. In 466, he married Leo I's daughter, Ariadne, with whom he had a son, Leo. On the death of Leo I in 474, Zeno's seven-year-old son took the throne as Leo II, with Zeno made co-emperor shortly after. Leo II died of an illness later that year, leaving Zeno as the sole emperor.

Julius Nepos (died 9 May 480), or simply Nepos, ruled as Roman emperor of the West from 24 June 474 to 28 August 475. After losing power in Italy, Nepos retreated to his home province of Dalmatia, from which he continued to claim the western imperial title, with recognition from the Eastern Roman Empire, until he was murdered in 480. Though Nepos' successor in Italy, Romulus Augustulus (r. 475–476), is traditionally deemed the last western Roman emperor, Nepos is regarded by some historians as the true last emperor of the west, being the last widely recognised holder of the position.

A native of Dalmatia, Nepos began his career as the semi-autonomous governor of the province, succeeding his uncle Marcellinus, a prominent general, as magister militum ('master of troops') of Dalmatia. After the death of the western emperor Anthemius (r. 467–472), who had been appointed by the eastern emperor Leo I (r. 457–474), as well as Anthemius' successor Olybrius (r. 472), Leo sought to assert his authority in the west, granting Nepos command of an army in December 473 to attack Italy and depose Glycerius (r. 473–474), who had been proclaimed emperor by the Burgundian general Gundobad. Nepos left for Italy in the spring of 474, backed by Leo's successor Zeno, and landed with his army at Portus, near Rome. Nepos swiftly deposed Glycerius and was crowned western emperor in Rome on 24 June 474. He was the last emperor to be crowned in the city until Charlemagne in the ninth century. Whether the original intention of the invasion was to install Nepos as western emperor is unclear, but in any event, he was quickly recognised as the legitimate western emperor by Zeno.

Aelia Verina (Greek: Βερίνα; died 484) was the Eastern Roman empress as the wife of Leo I. She was a sister of Emperor Basiliscus. Her daughter Ariadne also became empress. Verina was the maternal grandmother of Leo II.

Leo II (Ancient Greek: Λέων, Leōn; c. 467 – 474), called the Younger, briefly reigned as a child emperor of the Eastern Roman Empire from 473 to 474. He was the son of Zeno, the Isaurian general and future emperor, and Ariadne, a daughter of the emperor Leo I (r. 457–474). Leo II was made co-emperor with his grandfather Leo I on 17 November 473, and became sole emperor on 18 January 474 after Leo I died of dysentery. His father Zeno was made co-emperor by the Byzantine Senate on 29 January, and they co-ruled for a short time before Leo II died in late 474. He is sometimes surnamed with the epithet "the Small" (Latin: Minor; Ancient Greek: ὁ Μικρός), probably to distinguish him from his grandfather and augustus Leo I (Ancient Greek: ὁ Μέγας, romanized: ho Mégas, lit. 'the Great').

Leontia (Greek: Λεοντία, 457 – after 479) was the daughter of the Eastern Roman Emperor Leo I.

Patricius (Greek: Πατρίκιος, romanized: Patrikios; floruit 459–471) was an Eastern Roman caesar, the son of the powerful general Aspar, who for almost two decades was the effective power behind the throne of the Eastern Roman Empire. Of mixed Roman and barbarian origin, Patricius was destined for the imperial throne by his father. He rose to the rank of caesar under Emperor Leo I, before his father's murder in 471 led to his own downfall and possibly death.

Flavius Marcianus (Greek: Μαρκιανός, fl. AD 469–484) was a member of the Leonid dynasty. The son of the Western emperor Anthemius, Marcianus married Leontia, the daughter of the Eastern Roman emperor Leo I. He was consul twice, and in 479 unsuccessfully attempted to overthrow the emperor Zeno. After his capture he was forced to become a monk; he escaped and raised an army but was defeated and recaptured by Flavius Appalius Illus Trocundes. In 484, when the Isaurian general Illus revolted against Zeno, Marcianus was freed and Illus proclaimed him emperor, before deposing him in favour of Leontius.

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.