Theodosius II (Greek: Θεοδόσιος Β&# 39;, Latin: Flavius Theodosius, also translated as Theodosius III (April 401-450, July 28), the eldest son of Arcadius and grandson of Theodosius I. He reigned as Emperor of the Eastern Roman Empire from 408-450 and compiled the laws of the empire into the Codex Theodosianus in 438.

Theodosius II, born in Constantinople, died at the age of 49 from a horse fall in Constantinople. Arcadius (Emperor) was the eldest son and grandson of Theodosius I (Emperor), with his uncle being Honorius (Emperor). He reigned as the Emperor of the Eastern Roman Empire from 408 to 450.
In 421 AD, he married Eudocia (formerly known as Athenais, 393-460 AD) as his wife; My daughter is Leonia Odokhia (422-462 AD).
On January 10, 402 AD, he was appointed as a co ruler by Arcadius. From 408 AD onwards, he monopolized the imperial power in the eastern region. During his reign, he assisted the Western Empire in defense and betrothed his daughter to the Western Emperor Valentinian III.
Theodosius II compiled the laws of the empire into the Theodosian Code in 438. After Theodosius II, the status of Latin continued to decline and was gradually replaced by Greek.

Legal construction
In 426 AD, Theodosius II and Emperor Valentinian III of the Western Roman Empire published the Citation of Doctrines. At that time, the latter was still in its infancy, so the law was actually enacted by Theodosius II. This law stipulates that the answers of the five great legal scholars of ancient Rome have legal effect, while limiting the number of cited legal scholars, and also provides solutions for disagreements among the five great legal scholars. [1]
In the year 429 AD, Theodosius II appointed eight commissioners to be responsible for editing historical laws and the teachings of the sages, but due to a large plan, it was not completed. In the year 436 AD, he elected another 16 members to specialize in editing laws and granted the power to modify the original text, making the laws more clear and easy to implement. This work was completed in early 438 AD, and the Code was promulgated on February 15 of the same year, which came into effect on January 1, 439 AD; And with the approval of Emperor Valentinian III of the Western Roman Empire, this code also came into effect in its jurisdiction. This is the Code of Theodosius. [1]
Relationship with the Holy See
Theodosius II's father (Arcadius) and mother (Empress Eucdusa) once exiled the Archbishop of Constantinople, St. John Chrysostom, or his translation, to another land, and later died on the last journey of exile. Thirty years later, the remains of Cresostan were welcomed back by the Eastern Roman court, and Theodosius II personally went to welcome and pacify his parents, confessing their sins; At this point, the imperial power of Eastern Rome began to bow down to the religious power.

War and Diplomacy
During the early reign of Theodosius II, it was relatively peaceful. But in 431, the Huns, led by Uldin, attacked the province of Thrace in the Byzantine Empire (Eastern Roman Empire). Even attacked Constantinople, becoming a threat to the Byzantine Empire in a short period of time. Forced the Byzantine Empire to pay an annual tribute of 350 pounds of gold, which rose to 700 pounds four years later, and ceded large territories. In addition, it was promised that the Huns could engage in trade in some border cities of the Byzantine Empire. Until the death of Theodosius II, the successor emperor Marcian refused the conditions of tribute and trade. The Huns had not yet launched a war when King Attila suddenly fell ill and died in the summer of 453. Because Attila's sons were vying for power and profit, it ultimately led to the Byzantine Empire driving the Huns out of their territory, and the Hun Empire also collapsed.

After the death of Theodosius II, his sister Purcharia competed for the throne with eunuch Christophes. Pulkaria won, and her husband General Marcian became the next emperor.