7 things you didn’t know about Marcus Aurelius

General James Mattis once called Marcus Aurelius' Meditations the one book every American should read. Marcus Aurelius was a philosopher, but he was also a Roman emperor, who bore trials and tribulations throughout his life with a quiet strength that continues to inspire us.

Here are seven things to know about the life of Marcus Aurelius.

1. He was adopted into the imperial family

In the Roman Empire, it was common for the emperor to adopt the man who would later become his heir. At just seventeen years old, the philosophically-minded Marcus Annius Verus was adopted by Antoninus Pius, himself the adoptive son of then-emperor Hadrian. Marcus was renamed Marcus Aurelius, or Marcus the Golden. After Hadrian died and Pius became the emperor, Marcus and his adoptive brother Lucius became successors to the throne. During his time as the imperial heir, the emperor taught Marcus the importance of self-discipline and civic virtue, qualities he would later come to exemplify.

2. He was a co-emperor with his brother

When Antoninus Pius died in 161 AD, Marcus and Lucius became co-emperors. Marcus was an impressive man of impeccable character, who shared his power with Lucius and the Roman Senate and used his power for the benefit of the empire. He was keen on administration but naive in war, having never commanded his own army or province during Pius' long and peaceful reign. But when war came to Rome, Marcus did not fail in his duty.

3. He faced threats from all directions

In the same year Marcus and Lucius became emperors, the king of Parthia invaded the Roman-controlled Kingdom of Armenia, and replaced its king with a puppet. Despite the presence of hostile German tribes across the Danube River, Marcus withdrew three legions from the Danube front and sent them to Armenia under Lucius' command. Lucius defeated the Parthians and pushed them out of Roman territory for the next thirty years. Only five years later Rome was invaded by the Marcomanni, a confederation of German tribes. Marcus raised two legions for war, but an epidemic in the empire forced him to wait an entire year before advancing.

4. He was forced to fight Rome’s enemies alone

In 168 Marcus and Lucius finally left for the German front, but were forced back due to the spread of the disease. One year later, Lucius was dead of smallpox and Marcus was the sole emperor of Rome. He never took this responsibility lightly. Now alone, Marcus marched to push the Germans back across the Danube. After a rocky start, the Romans were able to turn the tide of the invasion. Marcus and his legions crossed the Danube, fighting some tribes and negotiating with others to turn the Marcomanni against one another. In 175 he negotiated a peace that allowed thousands of Roman soldiers to return home along with many Germanic warriors to serve in Rome's legions.

5. He never had the chance to relax

Just as Marcus made his peace with the Germans, there was a rebellion in Syria. Marcus started the journey east to quell the rebellion, only for it to be suppressed before he arrived. Nevertheless he continued his tour of the east to provide the people with an image of strength. He would need his own strength when on the tour his wife Faustina died in 175. Their relationship had been difficult, but he faithfully mourned her death. For the first time in eight years, and now completely alone, Marcus returned to the city of Rome. He could enjoy a brief respite, but it would not last.

6. He spent the rest of his life at war

In the year 177 there was another Germanic rebellion which forced Marcus Aurelius to leave Rome. He would never step foot in the city again. For the next few years, the Romans fought the rebellious tribes in their own territory. The war seemed to be going well until March 17, 180, when Marcus Aurelius died from a mysterious illness in the military outpost of Vindobona. His years of warfare brought him no pleasure, but his sacrifices bought time for an empire that in the coming years would descend into chaos.

7. He is still remembered today

Marcus Aurelius is known as the last of the Five Good Emperors. Even in his own time he was considered an ideal philosopher-king, who always placed his duty above himself. Today he is most famous for his Meditations, the modern name for the private journal he kept during his time on the German front. In this journal he shared his deepest thoughts, on the challenges he faced as an emperor and as a man, and how he struggled to overcome them. Marcus' Meditations was written to himself, but is really a universal letter to humanity about life and holding one's head up despite it all.