Magister militum in the context of "Leonid dynasty"

Romulus Augustus (c. 460-465) – (c. 511-530), nicknamed Augustulus, was Roman emperor of the West from 31 October 475 until 4 September 476. Romulus was placed on the imperial throne while still a minor by his father Orestes, the magister militum, for whom he served as little more than a figurehead. After a rule of ten months, the barbarian general Odoacer defeated and killed Orestes and deposed Romulus. As Odoacer did not proclaim any successor, Romulus is typically regarded as the last Western Roman emperor, his deposition marking the end of the Western Roman Empire as a political entity. The deposition of Romulus Augustulus is also sometimes used by historians to mark the transition from antiquity to the medieval period.

Very few records survive of Romulus's reign. There are no known policies, laws or inscriptions of significance of the emperor, which leaves the impression that he was a shadowy and relatively inconsequential figure. The nickname "Augustulus" means "little Augustus" and was a derisive reference to his young age. Romulus's immediate family, including his father and possibly his mother, and maybe both his paternal and maternal grandparents, were from the Roman province of Pannonia, and many of his family members had military backgrounds.

Gainas (?-400 AD, Greek: Γαϊνάς) was a Gothic leader who served the Eastern Roman Empire as magister militum during the reigns of Theodosius I and Arcadius. He played an important role in the events in the eastern part of the empire by the end of the 4th century.

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.

Theodoric (or Theoderic) the Great (about 454 – 30 August 526), also called the Amal, was king of the Ostrogoths (475–526), and ruler of the Ostrogothic Kingdom of Italy between 493 and 526, regent of the Visigoths (511–526), and a patrician of the Eastern Roman Empire. As ruler of the combined Gothic realms, Theodoric controlled an empire stretching from the Atlantic Ocean to the Adriatic Sea. Though Theodoric himself only used the title 'king' (rex), some scholars characterize him as a Western Roman emperor in all but name, since he ruled a large part of the former Western Roman Empire. He also received and used the former Western imperial regalia from Constantinople in 497, and exercised imperial powers recognized in the East, such as naming consuls. The Italian aristocracy referred to him using the imperial title princeps .

As a young child of an Ostrogothic nobleman, Theodoric was taken as a hostage to Constantinople, where he spent his formative years and received an East Roman education (paideia). Theodoric returned to Pannonia around 470, and throughout the 470s he campaigned against the Sarmatians and competed for influence among the Goths of the Roman Balkans, gaining recognition as king in 471. The emperor Zeno made him commander of the Eastern Roman forces in 483 and consul in 484. Nevertheless, Theodoric remained in constant hostilities with the emperor and frequently raided East Roman territory.

Flavius Ardabur Aspar (Greek: Ἄσπαρ, fl. 400 – 471) was an Eastern Roman patrician and magister militum ("master of soldiers") of Alanic-Gothic descent. As the general of a Germanic army in Roman service, Aspar exerted great influence on the Eastern Roman Emperors for half a century, from the 420s to his death in 471, through the reigns of Theodosius II, Marcian and Leo I, who, in the end, had him killed. His death led to the ending of the Germanic domination of Eastern Roman policy.

Byzantine rule in North Africa spanned around 175 years. It began in the years 533/534 with the reconquest of territory formerly belonging to the Western Roman Empire by the Eastern Roman (Byzantine) Empire under Justinian I and ended during the reign of Justinian II with the conquest of Carthage (698) and the last Byzantine outposts, especially Septem (708/711), in the course of Islamic expansion.

The region's administrative structure was initially in line with the typical late Roman administrative structures that had been existing for the past 300 years. Civil powers were thus in the hands of a Praetorian prefect, the head of the supreme civil administrative authority in the Late Roman Empire. The military powers, however, were incumbent on a Magister militum per Africam. These powers were merged into single office from 591 at the latest, and East Roman North Africa became the heartland of one of two exarchates, with the founding of which the East Roman Emperor Maurice (582–602) was able to counteract the consequences of imperial overstretch through bundling and decentralization. No further change in these administrative structures took place until the end of Byzantine rule.

Constantius III (died 2 September 421) was briefly Western Roman emperor in 421, having earned the throne through his capability as a general under Honorius. By 411 he had achieved the rank of magister militum, and in the same year he suppressed the revolt of the usurper Constantine III. Constantius went on to lead campaigns against various barbarian groups in Hispania and Gaul, recovering much of both for the Western Roman Empire. He married Honorius' sister Galla Placidia in 417, a sign of his ascendant status, and was proclaimed co-emperor by Honorius on 8 February 421. Constantius reigned for seven months before dying on 2 September 421.