In the early years of the Roman Empire, political power often shifted rapidly and was sometimes secured through unconventional means. One man, Lucius Aelius Sejanus, stands out as someone who quietly rose from relative obscurity to a position of great influence under Emperor Tiberius. Through careful maneuvering and calculated actions, he changed both his own fortunes and those of the Praetorian Guard, shaping the future of Rome’s leadership.
Sejanus transformed the Praetorian Guard into a true force within the empire and became a central figure in the imperial court. His involvement in high-level politics, personal rivalries, and secret plots left a lasting impact, demonstrating how ambition and calculated alliances could challenge even the established order of Rome.
Key Takeaways
- Sejanus increased the power and organization of the Praetorian Guard.
- His political skills allowed him to become very close to the emperor.
- Ambition and rivalry eventually led to conspiracies and major changes in Rome.
Sejanus’s Path to Power
Roots and Family Ties
Lucius Aelius Sejanus was born in the Etruscan city of Volsinii. He came from a family with strong political ties. His relatives included consular ancestors and powerful in-laws, such as Julius Plautius, the governor of Pannonia.
Sejanus’s father also held high positions, and Sejanus grew up surrounded by influential family members. These connections helped him build a solid foundation for his future career.
Key Family Connections:
| Relative | Position |
|---|---|
| Father (L. Seius Strabo) | Praetorian Prefect, later governor |
| Julius Plautius | Governor of Pannonia |
| Consular Relatives | Various top Roman offices |
As a young man, Sejanus reportedly accompanied Gaius Caesar, Augustus’s grandson, on a trip to the East. This early exposure to politics and the imperial family gave him experience and important contacts.
Beginning his Service with the Imperial Guard
Sejanus started his career in the Praetorian Guard under Emperor Tiberius. At first, he served alongside his father. Together, they commanded the Praetorians, who protected the emperor and played a major role in Roman politics.
When Tiberius needed help stopping a military mutiny, Sejanus was sent along with Drusus, Tiberius’s son, and Praetorian cohorts. This event marked the first time the imperial guard was used in the field, highlighting Sejanus’s importance and trust within the emperor’s circle.
After his father left to serve as governor of Egypt, Sejanus became the sole commander of the Praetorians. He took steps to make the Guard stronger and more united, gathering them in a new camp in Rome known as the Castra Praetoria.
- Key actions:
- Used his influence to secure high offices for family members
- Responded quickly to emergencies like the fire in Pompey’s theater
- Earned praise from the Senate and Emperor
Sejanus’s leadership, political skill, and family background allowed him to gain more power within Rome, setting the stage for greater ambitions.
Changes in the Praetorian Guard
Augustus and the Start of the Imperial Bodyguard
Augustus saw the problems the Roman legions caused inside Italy before he became ruler. To fix this, he created a new military force—special groups known as the cohortes praetoriae. These soldiers became the Emperor’s trusted protectors and were kept outside Rome to avoid the appearance of a military dictatorship.
By the year 14 AD, when Augustus died, the Praetorian Guard was led by two men. Both were of equestrian rank, and one of them was Lucius Seius Strabo, who would later be succeeded by his son, Sejanus.
Key Changes by Augustus:
- Formed a loyal guard for the Emperor
- Stationed the Guard in provinces, not Rome
- Chose leaders from the equestrian class
Sejanus Gains Complete Control
After Strabo left to become the governor of Egypt in 15 AD, his son Sejanus became the only commander of the Praetorian Guard. Over time, Sejanus grew even more powerful. He helped his family gain top political jobs and led the Guard during emergencies, such as the fire at the Theater of Pompey, where his quick actions were praised by the Senate.
With Emperor Tiberius growing older and losing many friends, he depended more on Sejanus. Sejanus was efficient and loyal but was not seen as a threat like many senators. This allowed him to become the Emperor’s top helper and expand his own influence.
Sejanus’s Actions:
- Used his position to help family members get high office
- Won public praise for handling city crises
- Built trust with Tiberius by being independent but loyal
Building the Praetorian Guard Camp
In 23 AD, Sejanus made a significant move for the Guard and for himself. He gathered all the separate Praetorian units into a new, massive camp in Rome called the Castra Praetoria. This camp was surrounded by strong walls and placed all the guards together, making them a more united force.
Castra Praetoria Provided:
- A central, fortified base in the city
- Greater ability to act together
- Increased the Guard’s power in politics
Table: Key Effects of the Camp
| Change | Result |
|---|---|
| All cohorts together | Stronger teamwork and loyalty |
| Fortified headquarters | Quick response to threats in Rome |
| Central location | Higher influence over political events |
The creation of this camp not only improved their military strength but also helped Sejanus use the Guard for his own goals and to shape events in Rome.
Political Influence and Goals
Interactions with Tiberius
Sir Janus earned early trust from Tiberius by acting as a guardian to his son Drusus during times of unrest. Tiberius saw him as a reliable figure, favoring his practical approach and clear independence. Sir Janus’s equestrian rank also helped reduce suspicion in the Emperor’s eyes compared to higher-ranking senators.
Key points:
- Trusted advisor to Tiberius
- Tasked with important missions
- Viewed as loyal, but not overly flattering
Tiberius depended increasingly on Sir Janus as he became more withdrawn and isolated from others at court. The partnership was built on mutual benefit, but it also gave Sir Janus more influence than nearly anyone else in Rome.
Securing Authority and Ambition
Sir Janus made strategic moves to strengthen his control, including bringing all Praetorian Cohorts together into one fortified camp. This action not only increased the guard’s strength and unity, but also made Sir Janus even more powerful in Rome.
Ambitious Actions by Sir Janus:
| Action | Goal |
|---|---|
| United the Praetorian Guard | Centralized military influence |
| Placed relatives in key positions | Extended his network |
| Handled public crises effectively | Increased public favor |
Sir Janus worked to clear paths to further power. He aimed to remove rivals—including Tiberius’s own son Drusus—by forming secret alliances and even orchestrating Drusus’s quiet elimination. With key competitors out of the way, Sir Janus set his sights on even higher roles, hinting at goals that reached the very top of Roman authority.
Tensions Among the Ruling Family
Power Struggle with Drusus
Lucius Aelius Sejanus and Drusus, the son of Tiberius, had a tense relationship. Drusus did not hide his anger about Sejanus having so much power with his father. Their arguments became personal, and Drusus even tried to strike Sejanus during one heated moment.
Sejanus, in turn, worked to sideline Drusus politically. Their conflict was not just about personal dislike; it was a fight over influence and control near the top of Roman leadership.
Key Points:
- Drusus was seen as the natural successor to Tiberius.
- Sejanus viewed Drusus as an obstacle to his ambitions.
- Their rivalry grew more intense as both gathered supporters in Rome.
| Rival | Motivation | Action |
|---|---|---|
| Drusus | Protect his position | Public hostility toward Sejanus |
| Sejanus | Gain greater power | Tried to isolate Drusus politically |
Secret Relationship with Livilla
To break Drusus’s power, Sejanus began a relationship with Drusus’s wife, Livilla. The reasons Livilla joined Sejanus are not clear. Possible reasons include wanting safety for her children, reactions to her husband’s temper, or simply choosing Sejanus on her own.
With Livilla’s help, Sejanus planned a plot. They decided that Drusus should be killed by poison in a way that looked like a natural illness. The plan succeeded, and Drusus died slowly over several days.
Events in Sequence:
- Sejanus gains Livilla’s trust and help.
- They secretly agree to remove Drusus.
- Drusus is poisoned and dies, opening the path for Sejanus to gain more influence.
Livilla’s role in this plot was crucial. With Drusus gone, Sejanus became even closer to the center of power.
Plot and Death of Drusus
Reasons Behind the Scheme
Lucius Aelius Sejanus saw Drusus as the main obstacle to his power. Drusus was not only the trueborn son of Tiberius, but he had also been marked as the likely successor with increased powers and honors. Tensions between Drusus and Sejanus ran high. Drusus strongly disliked Sejanus and even once tried to strike him during a heated argument.
Sejanus used this rivalry to his advantage. He formed a relationship with Drusus’s wife, Livilla. With Livilla’s help, Sejanus aimed to remove Drusus and clear his own path to greater control.
Carrying Out the Plot
Sejanus and Livilla made plans to kill Drusus using poison. The method was chosen because its symptoms could easily look like a natural illness. In early September 23 AD, Drusus’s wine taster gave him the poisoned drink.
Timeline of the Assassination
| Event | Details |
|---|---|
| Affair with Drusus’s wife | Sejanus gained Livilla as an ally |
| Selection of poison | To mask murder as natural causes |
| Delivery of poison | Administered in Drusus’s wine |
| Drusus’s decline | Became ill over several days |
| Death of Drusus | Passed away from the poison |
After Drusus died, Tiberius believed his son had died of sickness. The plot remained hidden, and Sejanus succeeded in removing a key rival without raising suspicion.
Sejanus’ Actions to Control the Line of Succession
Undermining Germanicus’ Descendants
Sejanus saw members of Germanicus’ family as the main rivals blocking his path to greater power. He knew that imperial bloodlines gave Germanicus’ relatives, especially his brother Claudius and Germanicus’ children, strong claims to the throne. Claudius had health problems and Germanicus’ children were still young, but their family ties posed real danger to Sejanus’ ambitions.
Sejanus targeted Drusus, Tiberius’ son, because Drusus held shared consulship and special powers, positioning him as the next emperor. Sejanus formed a close alliance with Drusus’ wife, Livilla, convincing her to join a plot against her own husband. Together, they arranged to have Drusus secretly poisoned in 23 AD. After Drusus’ death, suspicions were covered up so that Tiberius believed his son had simply died from illness.
Below is a brief summary of Sejanus’ strategy:
| Step | Action |
|---|---|
| Identify Rival | Focus on Drusus as main threat |
| Gain Ally | Influence Livilla, Drusus’ wife |
| Remove Threat | Secretly poison Drusus |
| Hide Plot | Conceal murder as natural illness |
Drusus’ removal left the field open for Sejanus, but there were still other key members of Germanicus’ family to weaken.
Cutting Off Agrippina’s Support
After Drusus’ death, Agrippina, the widow of Germanicus, became Sejanus’ next focus. Agrippina was respected and had strong support from soldiers who remembered her husband’s command. Sejanus saw her as a symbol of opposition to Tiberius, and therefore a threat to his own influence.
Sejanus worked to convince Tiberius that Agrippina and her allies were plotting against the emperor. He whispered suspicions about her loyalty and painted her as a leader of a rebellious group. With Tiberius’ trust, Sejanus started to remove those close to Agrippina one by one.
Key points in Sejanus’ campaign against Agrippina:
- He accused her supporters, starting with high-profile figures.
- He used his position to isolate Agrippina from the emperor and from sources of power.
- Loyal followers of Agrippina were charged with crimes and removed from court.
These moves weakened Agrippina’s influence within the imperial family and made her more vulnerable, paving the way for Sejanus to get even closer to absolute power.
Lasting Impact of Sejanus and the Praetorian Guard
Sejanus changed the role of the Praetorian Guard in Roman society. Before his time, the Guard had been scattered around Italy. Sejanus gathered all the cohorts into the new, fortified camp called the Castra Praetoria in Rome. This move made the Praetorian Guard more organized and powerful.
Key Changes Introduced by Sejanus:
- Centralized the Guard’s location inside Rome
- Strengthened their influence on politics and the emperor
- Used the Guard for domestic emergencies, like stopping the fire in Pompey’s theatre
Sejanus used his position to help his family and build his career. He helped his uncle become governor of Africa, and he gained more attention from Emperor Tiberius after saving Rome from the fire.
His actions made the Praetorian Guard a key political force. Tiberius trusted Sejanus, even as others, such as Drusus, viewed him with suspicion. Sejanus’s rise showed later leaders in Rome how important the Guard could become in the struggle for power.
| Action | Result |
|---|---|
| Built Castra Praetoria | Made the Guard more unified and central to Rome |
| Helped during crises | Earned praise and political rewards |
| Influenced appointments | Boosted family and allies |
From Sejanus’s time forward, the Praetorian Guard would have a major role in Roman politics. Their power grew, setting a pattern that continued for centuries. Sejanus’s career marked the start of the Guard’s ongoing influence over emperors and succession.
