House of Theodosius
In many ways, the history of the House of Theodosius is a direct continuation of that of the Valentinian Dynasty. It's tempting to lump them all together since the Valentinians became Theodosians, but it's more accurate to label them separately. The time in which the Theodosians came to power was a time of great and sometimes painful change for the Roman Empire. After the death of the founding member of the dynasty, the Empire would permanently split into two distinct states and would come to have increasingly less and less to do with one another except in a pro forma sense.
Flavius Theodosius was a military commander appointed to his position during the reign of the Western Roman Emperor Valentinian I. He is generally known as Count Theodosius to distinguish himself from his son of the same name. The term "Count" is sort of an anachronism since the title he actually held was comes, which had a different meaning in his own time (the mid-to-late fourth century) than it would later on. In 368, the Emperor sent him to Britannia to counter a Pictish invasion and recapture a renegade province, which he accomplished in fairly short order. Both the younger and the elder Theodosius participated in the British campaign and the latter began to make a name for himself. Later, when the province of Africa revolted against him, Valentinian sent the Count to bring the rebels in line. Then, around 375, a strange thing happened: Theodosius was forced into retirement and his father, the Count, was executed in Carthage on the Emperor's command. We're not sure what happened, but it seems as though the younger Theodosius had been among the first to call for a retreat during a battle in the African campaign and when his father attempted to intervene on his behalf, the notoriously ill-tempered Emperor had him killed.
Whatever the case, Theodosius' "retirement" turned out to be anything but. In 379, Theodosius was called upon to succeed the late Eastern Emperor Valens, who had recklessly thrown himself into the Battle of Adrianople without waiting for the badly needed reinforcements his co-ruler Gratian was bringing from Gaul. Theodosius and Gratian met up and resumed the attack, eventually winning the day. Gratian died in 383 after being overthrown by one of his own generals, and his brother Valentinian II came to Constantinople to live with Theodosius. In 385, Theodosius' wife died and he married Galla, the daughter of the elder Valentinian. In 388, Theodosius met the Western usurper in battle and defeated him, restoring his brother-in-law to his previous position.
In 391, Theodosius became the first Emperor to publicly outlaw paganism throughout the Empire and make Orthodox Christianity the official state religion. Though his deprivation of the pagan temples' income was harmful enough, his most psychologically damaging act was the extinguishing of the Eternal Flame of Vesta. Although this was surely a controversial move, it would be overshadowed by the events of the next year. In 392, Valentinian was found dead in the Western palace. His chief minister, a Frank named Arbogast, alleged that the Emperor had killed himself, but Theodosius believed Arbogast was responsible as he knew that Valentinian had had numerous personal and political conflicts with him. Arbogast was an unsuitable candidate for Emperor, so he nominated an obscure politician named Eugenius to succeed Valentinian and sent a delegation to Constantinople to win Theodosius' approval. He agreed and sent them back to Rome. He then immediately made plans to invade the West and destroy the usurpers. He accomplished this in 394 and named his son Flavius Honorius Western Emperor at the age of nine. Though young, Honorius already held extensive governmental experience: he had been consul at the age of 2, so he was clearly a savvy political operator.
An Important Pet Chicken
In 395, Theodosius died. He was succeeded by son Flavius Arcadius in the East. Neither of Theodosius' young sons cut very impressive figures. Let's step back and consider things for a moment: when Rome first became an Empire in the year 27 BC, the leadership position in place was an ostensibly Republican office called the Princeps, which meant the First Man in the Roman Senate. Had he been buried rather than cremated, Augustus would turn over in his grave at the thought of a 10 year old child leading the mightiest Empire the world had ever seen up to that point straight into its grave. It's really not fair to blame Honorius and Arcadius for poor management of their Empires, as they were simply both too young to understand the stakes. Theodosius bears at least some of the responsibility as he put filial ties above the interests of the state in picking his successors. Either way, both of his sons were completely dominated by their powerful ministers for most of their reigns. Flavius Stilicho was a Vandal general and "advised" Honorius on important matters of state, eventually marrying his daughter to the Emperor to have his own genetic foot in the dynastic door. Arcadius' adviser was a man named Rufinus who exercised a similar influence on him, although his wife was also overbearing and influential. Honorius and Arcadius were both aloof and distracted, although the former was more interested in indolent, vapid pursuits of pleasure while the latter was more interested in Christian piety.
Stilicho had Rufinus killed in the first year of Arcadius' reign and briefly considered going to war against the Eastern Empire. Times were tense, but Arcadius' new chief adviser, Anthemius, got on well with Stilicho and the issues between the head Imperial ministers ceased. Arcadius died in 408 at the age of 30 and the cause is unknown. He was succeeded by his 7 year old son Flavius Theodosius II, though Anthemius continued to call the shots in the Eastern Empire.
Things were going quite poorly in the West at this point. Stilicho, despite his detrimental political influence on the Emperor, was an able military man and was required to deal with several threats to Imperial rule during Honorius' reign. Any real successes that happened during this time can readily be attributed to Stilicho rather than Honorius. Really, it's impossible to go through all of the revolts and attempted usurpations of the Western Empire in any short manner, so I'll deal with the three most series occurrences. First, in 408, Honorius accused Stilicho of conspiring to usurp his throne, and had him executed. This does not seem to have been true at all, but Honorius believed it, and the Western Empire lost its only capable defender. Next, in 410, mounting pressures in Gaul forced the complete Roman abandonment of Britannia, which Rome had held continuously since the reign of Claudius in the first century. This had a hugely negative impact on the Island, which would be caught in a state of constant strife for hundreds of years as a result. Finally, the worst and most humiliating occurrence of Honorius' reign came later in the year 410 when Alaric, the King of the Visigoths, sacked the city of Rome. Rome was not the administrative center of the Western Empire by this point, so Honorius was not in any personal physical danger. However, it was a crushing blow to Roman morale, which was already strained to the breaking point. It is said that when Honorius was informed that "Rome has died," he was shocked and deeply saddened. He evidently had a beloved pet chicken by the same name and when he was informed that the chicken was alive but that the actual city had been overrun, he expressed great relief. Whether this is true or not is debatable (and I'm not inclined to believe that it is), but the fact remains that it reflects attitudes toward Honorius as well as the unfortunate situation in which the Empire found itself.
In the East, the minister Anthemius either died or fell out of favor, and is not heard from again after 414. The main center of power in Constantinople became not the Emperor, but rather the Emperor's sister Pulcheria. Pulcheria was an intelligent and able administrator, having been named Augusta in the same year as Anthemius' fall. She was known for her extreme piety, devoting herself to lifelong chastity and taking harsh measures against anyone who publicly displayed or professed anything other than Orthodox Christianity. She also seems to have picked out a wife for her brother, a certain Eudocia, though she would come to regret this choice in later years as they would not see eye to eye on religious matters or Theodosius' policies.
Speaking of marital arrangements, in the year 417, Honorius had his sister Galla Placidia marry Flavius Constantius (unrelated to previous rulers of the same name). Like Stilicho, Constantius was a military man of some ability; unlike Stilicho, however, he seemed to have no aspirations to rule. Despite this fact (or perhaps because of it) Honorius promoted him to be his co-Emperor in 421. Constantius III seems to have hated the promotion, since it quickly became clear that his so-called colleague was more interested in partying than governing, and thus the responsibilities of the state fell almost solely on his head. Theodosius (now an adult) did not acknowledge Constantius as co-Emperor. It didn't really matter that much because before the end of the year, Constantius was dead from an unspecified illness. Galla had by this time given birth to a son, Placidus Valentinianus, and after the death of his father, Honorius effectively named his young nephew as his successor, a claim which was also rejected by Theodosius. In the same year, the King of Persia (who had maintained a policy of non-confrontation with the Romans) died and his successor immediately began to attack the East. Then, something that could be perceived as being either good or bad happened: in the year 423, Honorius died of edema. Theodosius came to regret his previous rejection of his cousin Valentinian III since an usurper named Ioannes seized Ravenna, the administrative capital of the Western Empire, and Valentinian and his mother fled to the East for protection. Theodosius had a change of heart and recognized his nephew as the legitimate claimant to the Western throne and marched against Ioannes.
As a brief digression, in the year 423, a cousin of Theodosius' (whose name has been lost to history) ascended to the Papacy, reigning as Pope Celestine I. The Theodosians controlled three of the most important positions in all of Europe: both Eastern and Western Emperorships as well as the Bishopric of Rome. Though Celestine didn't do anything really great as Pope, he was still made a Saint and this is the beginning of the politicization of the Papacy.
Shift of Power
Around this time, a new figure appeared on the scene: Flavius Aetius was a military man who had initially supported Ioannes but defected to Valentinian's camp in 425 when Ioannes was defeated and killed by the combined forces of the Eastern and Western Empires. Aetius was able to secure a pardon for himself because of a personal appeal to Placidia and his important Hunnic connections. The Huns were becoming something of a menace to both the East and the West, since their entire economy was based on war and the plunder they gained as a result of it. The Huns were a ferocious enemy, preferring short but devastating campaigns to make as much of an impression as possible. They had no territory to defend, per se, so it was difficult to track them down to any central location and extinguish them. In fact, the Eastern Empire paid tribute to the Huns to keep them away, certainly a humiliating state of affairs. Aetius had been raised among the Huns as a hostage, and had a good rapport with their leaders as well as a sophisticated understanding of their tactics. These resources would prove invaluable in the coming years.
Aetius had powerful enemies, however, the most significant of which was Count Boniface, a Roman governor and military commander in Africa. Aetius convinced Placidia to charge the Count with treason for some reason or another, and in response, Boniface entered into open rebellion against the Empire, calling in his Vandal allies as reinforcements. By the time they got there, however, Placidia had withdrawn the charge and had pardoned him as well. When he told the Vandals this, they were enraged, and overran the province of Africa, ejecting the Romans from the area and not losing control of it until a century later. As the Count made his return to Europe, Aetius decided the time was ripe to destroy him, and in 432, the two armies met in Rimini. Unfortunately for Aetius, the Count prevailed, and he had to beat a hasty retreat to Croatia. On the other hand, Boniface was seriously injured in the fighting and died. Placidia had tacitly supported Aetius and restored him (and his Hunnic soldiers) to favor. Aetius would go on to become the dominant personality in the Western Empire, much like Stilicho had been under Honorius. And like Stilicho, Aetius would meet his end at the instigation of those who had formerly benefited the most from his deeds.
End of the Dynasty
I started out by saying that the history of the House of Theodosius is a continuation of the history of the Valentinian Dynasty. While this is true, it's also the story of the beginning of the fall of the Roman Empire. Theodosius decided that it was of the utmost importance for the laws of both Empires to be consistent and readily disseminatable, so he had legal scholars from both East and West codify everything into one canon of law, and it became collectively known as the Codex Theodosianus. The significance of this achievement would not be fully appreciated until the reign of the Byzantine Emperor Justinian I, who would refine it into the superior Corpus Juris Civilis. Theodosius died as a result of an injury sustained from falling off of his horse in 450 and was succeeded by Flavius Marcianus, a general who married Pulcheria to advance the legitimacy of his claim. Marcian, as he was known, found the idea of a mighty Empire like Rome paying tribute to the Huns absurd and discontinued the practice. This was quite a gamble on Marcian's part, because on the face of it, it would seem as though the Huns would be heavily inclined to punish the Emperor for his insolence. This actually turned out not to be the case, however, as a campaign against the East would be completely out of character for the Huns. Constantinople was heavily fortified and surrounded by water on three sides and any attack on it would be neither short nor beneficial for the Huns. They fatefully decided to turn their attentions to the Western Empire.
This was a personal blow to Aetius, who by this time was the chief minister of Valentinian III, because he had been close with the Huns and had relied on them for auxillary support in some of his campaigns. The West was in great trouble by this point, having lost essentially all of its territories save for Italy and a rump state in Brittany called the Domain of Soissons, which was not physically connected to the rest of the Western Empire (if indeed the term is appropriate). The leader of the Huns was Attila, a childhood friend of Aetius. Attila needed a pretext for attacking the West and received it in the form of a bizarre letter from Valentinian's sister Justa Grata Honoria. Honoria was fed up with life at the court and refused to be married off to an obscured Senator. She sent her personal ring to Attila and complained of all the injustices carried out against her by her brother, asking if he would be her champion. Attila interpreted this as a marriage proposal and accepted. He sent a letter to Valentinian, telling him that he would be happy to marry his sister! What a joyous day! He mentioned that he was interested in his dowry, which he fairly assessed as half the territory of the Empire. Valentinian flew into a rage and initially wanted to execute Honoria, but his mother restrained him, warning him of the scandal that would erupt as a result.
Valentinian informed Attila that the marriage was out of the question and his idea that he was in some way entitled to half the Empire was ridiculous. Attila was offended and invaded the Empire in 452. Aetius was called upon to deal with him. Attila raped and pillaged the Italian countryside, and Aetius pursued him with a Fabian strategy of picking off his men and then retreating before anybody could do anything about it. Attila seemed sure to prevail, but bizarrely, Pope Leo I convinced him to abandon the campaign, which he did. Attila died in 453 in unclear circumstances, possibly from liver failure or edema. Then, in 454, Valentinian abruptly killed Aetius during a meeting about Imperial finances, supposedly because he intended to usurp Valentinian's position and put his son on the throne. One of the witnesses of the killing remarked to the Emperor "I don't know why you did that, but you remind me of a man who has cut off his right hand with the left." Indeed, beyond that, Valentinian had signed his own death warrant as two of Aetius' officers would assassinate him the very next year. The House of Theodosius thus crumbled on its foundations and irrevocably set the course for the death of the Western Roman Empire.
The Theodosians shared many characteristics with other dynasties of the Roman Empire. The most common feature is the shared potential for greatness at the beginning and the complete inability of the initiator's successors to match his achievements. The main exception to this rule would be the Valentinians, who were pretty poor rulers all around. Theodosius I is sometimes called "the Great," although that depends on your point of view. In any case, it's difficult to deny in relative terms that he was better than his immediate predecessors and his immediate successors. He was unwise, however, in promoting his young sons to positions of high power, even if they were only meant to be figureheads until their maturity. It is a common feature of the middle and later Empire that young Emperors believed their role in wearing the Purple was to have as much fun as possible while other people handled little details like wars and not letting the economy completely collapse. It amazes me, personally, that Honorius died of natural causes as if any Emperor seemed the perfect target for assassination, it would have been him. The death of Valentinian in 455 gave rise to a handful of worthless and ineffectual rulers and usurpers before what is regarded as the ultimate fall of the Western Empire in 476. This terminology is controversial, but it's undeniable that something fundamentally changed in the West at that time -- Late Antiquity was over and the Dark Ages had begun.
Valentinian Dynasty | House of Theodosius | The Fall of the Western Roman Empire