I had an un-submitted blog post detailing about half of the history of the Roman Empire. It was a great wall of text even with spacing. So I decided to split it into many posts. First, let us go over the most famous period of the Roman empire, its first two centuries, the golden age know as the Roman Peace, or the Pax Romana. Despite its name, this era is not entirely devoid of civil strife, but it pales compared to the millennia following. Though it started in the ancient city of Rome, the Roman Empire was not to always be centered around the city. Similarly, the contemporary name of the Roman Empire was actually Romania (or in Greek, Rhomania), meaning Empire of the Romans. This reflects that the Empire was not completely tied to the city but the culture and the people that it had loosely united into one. More on this in later blog posts. Also, as Christianity was to later have a major role in the Roman Empire's identity, I will be giving samples of it's history during each dynasty.
Julio-Claudian Dynasty = 95~ Years
Now for the famous Julio-Claudians, founders of the Roman Empire and the beginning of the Pax Romana, the golden age of the Empire of the Romans. Many documentaries about this dynasty and the history of its rise to power exist, so I won't go into too much detail here. At the time called the Caesars, as this title would be used as the title of the Roman Emperors until the Third Century Crisis, they are remembered after their extinction as the Julio-Claudians. Starting from Octavianus to Nero, the dynasty lasted [68-14=54] | [27+14=41] | 54+41=95 years. Wow, I thought they lasted a shorter time. Not bad for a bunch of tyrannical nutjobs (though Octavian and Claudius were good, Tiberius was only good the first half of his reign, Nero and especially Caligula were indeed nutjobs). For giggles, we can include Julius Caesar from his 5 years rule as Dictator for Life, even though as the nominal dynasty founder he was never an emperor but a dictator who after his death would (unfortunately not) return back to Republican norms. 95+5=100, give or take months. Even without Julius Caesar, it's still impressive considering their inherent strain of madness.
The first land to be conquered by the Julio-Claudians was Egypt (under Augustus), and later Brittania would fall as well (under Claudius). Octavian would undergo two name add-ons, first adding the name Gaius Iulius Caesar to his to proclaim legitimate succession to Caesar's elgacy, then being awarded the title of Augusts by the Senate; in creating the Empire, he founded the Principate System, where the Emperor was supposed to be a guardian of the people and the Republic still functioned, but by stealthy skill he was to be the supreme dictator over all the realm, though local affairs would continue to carry true republican behaviors.
It was under this dynasty that Christianity emerged, during the time of Emperor Tiberius the messianic figure Yeshua Nazareni/Jesus of Nazareth was born Palestine and later emerged from the desert after a period of self-exile and proselytized for 3 years before his crucifixion, later titled Khristos or Annointed One by his loving followers. The first Christian persecution started when Caligula put pressure on them and killed a few Christians in the Levant for refusing to worship him, though at the time the Roman Empire did not separate Judaism and Christianity from one another. Later a Christian-specific persecution occurred under Nero, though it was local to central Italia, and it under Nero's orders that two Apostles were executed.
After toleration of his disturbed tyranny ran out, Nero ended up infuriating the government and it turned against him, he running for his life and locking himself in a building before killing himself to avoid an even more horrible end. The death of the emperor with no heir caused civil war, the Year of the Four Emperors.
Flavian Dynasty = 27 years
The Flavian dynasty, from Vespasian to Domitian, lasted 96-69=27 years. Though brief, this dynasty had a profound impact on the Roman Empire. Vespasianus, a general under under Claudius and Nero that assisted in the Empire's invasion of Britain and crushed most of the Jewish Rebellion; his son and heir Titus finishing Vespasian's campaign in Palestine to quell the Jewish revolt and bringing forth the prophecy of Jesus Christ in the destruction of Jerusalem and its second Temple (this having an affect in increased Christian conversion), the treasure from the temple being used by Vespasian to make the Flavian Amphitheater, aka The Colosseum. Vespasianus brought order after Nero's suicide, also brought back traditional Roman values to a long-decadent throne, and long served as an example of character down the millennia. His sons Titus and Domitian succeeded him, respectively.
Domitian in particular is remembered for dropping the Republican facade the Principate system was founded on while he ruled, seeing the Senate as nigh-worthless and tackled all projects personally head-on, likewise noted for his policy in low expansion, Britain and Dacia being the exception (a general of his named Agricola even set up a military camp on Irish shores but when Dacia went to war Hibernia/Ireland was forever abandoned, and likewise most of Caledonia/Pictland). The economic reforms of Vespasianus and Domitianus restored economic stability to the Empire after funds had been plundered by the Julio-Claudians, and the reforms also allowed for the golden age of the next dynasty, the Nerva-Antonine. A zealot for the Imperial cult, Domitian ruled the empire as a divine monarchy, and he is recorded by much later Christians chroniclers for starting a second persecution, though likewise only local; Roman records for this are scarce, but their records show extreme taxation for Jews and Christians. Killed by a Senate plot (no doubt because he had stripped them of their power), Domitian's assistant Nerva took over the same day.
Nerva-Antonine Dynasty = 96 Years
Nerva-Antonine Dynasty, from Nerva to Commodus, lasted 192-96=96 years.
A golden age of the Roman Empire (or 'golder', as it is already kind of a golden age), the Nerva-Antonine as they were called upon their extinction were renown for their notabilities are great leaders (though imperfect personally), but ended their line on a poor note. The highlights of this dynasty include the likes of Traianus/Trajan, Hadrianus, Marcus Aurelius, and infamously, Commodus. Traianus extended the empire to it's greatest length in his conquest of Dacia and Mesopotamia and solidifying an official, legal border. Hadrian reinforced this border solidification when not messing around with his pedophiliac child lover; Hadrian's most long lasting contributions would be the great fortifications known as Hadrian's Wall and Hadrianopolis in Europa Thraxia (Thrace) as well as reinforcing the Danuvian Limes (limes were Roman military borders with walls, trenches, and forts lining them). Antonius Pius, heir to Hadrianus and adopted father of Marcus, ruled in a time of great peace, expanded into Caledonia (modern Scotland) and built the Antonine Wall, which would later be abandoned and the border be brought back to Hadrian's Wall. Trajan also established a policy that people converting to Christianity were to be fined, and it is this relaxed stance on Christians that made medieval Papacy held that Trajan was a 'worthy heathen', and their contemporary traditions hold that a Pope resurrected Trajan and baptized him as a Christian.
Then famous Marcus Aurelius and Commodus, this father and son duo is famous from multitudes of media. Commodus, son of Marcus Aurelius, abandoned the conquests of his father as well as the Republican facade, dried Rome's coffers and was the first piece of a disastrous duo to cause the Third Century Crisis. He also cosplayed as Hercules in the arena. Even though there would be exceptions like Marcus Aurelius and much later Maximinus Thrax conquering Germania (though they be temporary), After the reign of Traianus the Romans would usually become less expansionist and more defensive, largely fighting to regain lost territory legalized as Roman by Trajan. Commodus would be assassinated while ina spa by his favorite wrestler, which a conspiracy involving the senate and his guard had paid to strangle him while the cucumbers were on his face. His death with no clear heir caused civil war, the Year of the Five Emperors.
Severian Dynasty = 42 years
Severan Dynasty, from Septimus Severus to Alexander Severus, lasted for 235-193=42 years.
Septimus Severus won a civil war following the murder of Commodus and stabilized the empire, something his successors would unravel at an increased rate. During his reign, Septimus Severus invaded Arsacid Iran and sacked their capital of Ctesiphon (nicknamed Mahuza, "The Cities", as when Ctesiphon grew it assimilated the previous Hellenistic city of Seleukia to become one metropolitan area), and reinforce the Arabian Limes and the African Limes. With the discord made with the Year of Five Emperors (which by its end Severus sealed power), Septimus Severus saw the need for religious (and thus, national) unity, so reformed the Roman faith to bring greater cohesion between its native cult and the religions of all those lands it ruled over; that is, save the exclusionist Christians, and he passed an edict to punish those that convert to either Judaism or Christianity but leave existing members alone (he protected Christians eh knew but this decree made many local persecutions rage across the Empire and the emperor did not lift a finger to help). He invaded Caledonia/Pictland (modern Scotland), reoccupying the Antonine Wall before falling fatally ill and dying in modern York.
One of the sons of Septimus Severus, Antonius "Caracalla", born with the confusing name of Marcus Aurelius Antonius Severus, was a grouchy man who loved to wear Roman-Gaelic clothing, mot notably a Gaelic cape called the caracalla, and he issued a law, the Antonine Constitution, that made all the free male denizens of the Roman Empire into voting citizens, and all free women enjoy the same the same rights as Roman women, rather than just those born in Italy. Because of this, all those that were affected had the name Marcus Aurelius added tot heir name, and those people named their children Marcus Aurelius or variations of it in gratitude to the fashionable grouch, (this made dating some things annoying when tracing things back to this man, any of all these multitudes of people, or the O.G. Marcus Aurelius. He was seen as a tyrant as he would not put up with any sort of disobedience after the 'gift' he gave to everyone and he ordered large-scale massacres across the empire throughout his reign at pockets who rose their voice to give concern or objection of policies.
Caracalla was assassinated by the head of the praetorian guard (the beginning fo a pattern), who himself declared himself Emperor and was later branded an enemy of the state and killed. The usurper was replaced by a distant relative of Caracalla, a Roman who worshiped Canaanite gods and who both was spoiled by his mother and abused his priestly powers. He was Elagabalus, named after the Canaanite sun-god El-Gabal, was a degenerate 13 year old priest of the Sun who made his religion of Sol Invictus the state faith, whose waste of funds and complete degeneracy are way too spicy for this website and brought great shame to the Empire of the Romans. The reign of Elagabalus is the other piece to the destabilization caused by the reign of Commodus, and despite the assassination of the tyrannical boy-emperor, all it took was a slip up in the form of his poor choice of legal heir, Alexander Severus, to cause the end of the world.