Theodosius I

Theodosius I, also known as Theodosius the Great, was Roman emperor from 379 to 395. He was an important leader who helped shape the future of the Roman Empire and the Christian faith. Theodosius was the last emperor to rule the entire Roman Empire before it split into two parts. He played a key role in making the Nicene Creed the main belief for Nicene Christianity.

Born in Hispania in 347, Theodosius grew up to become a strong and careful leader. He faced many challenges, including wars with groups like the Goths. In 395, Theodosius passed away, and his two sons, Arcadius and Honorius, took over ruling the empire from separate courts in the east and the west.

Theodosius was a devoted Christian and worked hard to support the Christian church. He helped make important decisions about Christian beliefs and built up the city of Constantinople, his main home. Even though he tried to keep the empire strong and united, after his death, the empire faced many difficulties, and the split between east and west continued until the fall of the Western Roman Empire centuries later.

Background

Theodosius was born in Hispania on January 11, probably in the year 347. His father, also named Theodosius the Elder, was a high-ranking general under the western Roman emperor Valentinian I. His mother was named Thermantia. The family were minor landed aristocrats in Hispania.

Not much is known about Theodosius's childhood. Some believe he grew up in his homeland, while others think he spent his early years with the army, joining his father on campaigns. He received a good education and developed a strong interest in history.

Career

Theodosius first appeared in history when he went with his father to Britain around 368–369 to help stop an invasion. After working with his father, Theodosius got his first big job in 374 as the leader of troops in Moesia Prima near the Danube. That year, he stopped an attack by the Sarmatians.

Theodosius was commander of the army in Moesia I in 374. His dismissal may have been connected to the accession of the emperor Valentinian II, which took place at Aquincum (Budapest) in nearby Pannonia Valeria, in 375.

Later, Theodosius’s father lost favor with the emperor and was removed from power. Theodosius went home to Hispania. Soon after, the man who may have caused his father’s trouble was removed from power. Theodosius returned to service and, in 377, was back leading troops.

When the eastern emperor Valens died fighting the Goths at the Battle of Adrianople in 378, Theodosius was chosen to take control. He became emperor on 19 January 379 after being approved by leaders at Sirmium and agreed to by the western emperor Gratian.

Reign

The administrative divisions of the Roman Empire in 395, under Theodosius I.

Gothic War (376–382)

When Theodosius became emperor, he had to deal with groups of Goths causing trouble in the Balkans. His army was weak after a battle called Adrianople. He made rules to get new soldiers and brought in people from outside the Roman Empire to help.

Theodosius and his generals fought the Goths and had some small wins, but sometimes lost battles. In 380, Theodosius got very sick but recovered. By 381, he moved his court to Constantinople and made peace with the Goths. They agreed to live in a part of the Roman Empire and help protect it in exchange for land.

Solidus of Valentinian II showing Valentinian II and Theodosius I on the reverse, each holding a mappa

383–384

In 383, Theodosius made his son Arcadius co-emperor. That same year, another emperor named Gratian was killed. Theodosius talked to the Persian emperor Shapur III to keep peace. He also tried to make peace between two other emperors, Valentinian II and Magnus Maximus.

Roman provinces along the Ister (Danube), showing the Roman dioceses of Thrace, Dacia, Pannonia and Italia Annonaria on the empire's northern frontier

Middle reign: 384–387

Theodosius’s second son, Honorius, was born in 384. Sadly, his first wife and their daughter Pulcheria died during this time. Theodosius settled more Goths in a place called Phrygia and celebrated victories in Constantinople. By the end of this period, Theodosius and his court were in Milan.

Civil war: 387–388

Solidus of Theodosius, showing both him and his co-emperor Valentinian II (r. 375–392) enthroned on the reverse, each crowned by Victory and together holding an orb victoria augg ("the Victory of the Augusti")

In 387, peace broke between Magnus Maximus and Valentinian II. Valentinian asked Theodosius for help, and Theodosius agreed. They got married, and Theodosius went to Italy to fight Magnus Maximus. In 388, Theodosius’s army defeated Maximus in a battle at Poetovio.

Massacre and its aftermath: 388–391

In 390, a sad event happened in Thessalonica. After a riot where a Roman officer was killed, Roman soldiers responded harshly. This event caused much discussion and concern among leaders and writers of the time.