Flavius Heraclius (Latin: Flavius Heraclius; Ancient Greek: Ηρパκλειος, 575 – February 11, 641), also known as Heraclius I, was the first emperor of the Heraclic dynasty of the Byzantine Empire (610-641).
Born into an Armenian family. Traditionally, Heraclius is considered the creator of the military district system, while modern scholars believe that it was only established during the reign of Emperor Constance II.

family origin
Heraclius was the eldest son of Heraclius the Elder and Epiphanes, and he came from an Armenian family in Cappadocia, possibly with Parthian ancestry. Besides, no one knows the specific information of his ancestors. His father was a key figure in the war against the Persian usurper Bahram during the reign of Emperor Maurice, which took place in 590 AD. After the war, Maurice appointed Heraclius as the Governor of Africa.
Seize political power
After the death of Emperor Justinian, the Eastern Roman Empire began to decline. In 602 AD, a highly motivated army was advancing southward on the Balkan Peninsula, fiercely shouting slogans against the emperor. Originally, this was a rebellious army of the Byzantine Empire. When they were ordered to winter in enemy territory on the other side of the Danube River, they openly rebelled under the leadership of centurion Phocas and marched towards Constantinople to deal with Emperor Maurice (the Phocas Rebellion). The military uprising in 602 was a product of the internal contradictions within the Byzantine Empire that had developed to a certain extent. With the support of the people of Constantinople, the army of Phocas quickly captured the capital and pushed Emperor Maurice, his children, and representatives of the government who were hostile to the army to the guillotine. Fukas became the emperor of the empire, and he brought about 8 years of bloody civil war.
Fukas, who had an illegitimate name and an unspoken reputation, was fiercely opposed by the Imperial Senate, nobles, and administrative bureaucrats from the beginning. They quickly provoked civil wars in various eastern provinces, including Syria, Palestine, Silesia, Asia Minor, Egypt, and others. The Byzantine Empire's long-time rival, Sassanid Persian Emperor Khusrau II, took the opportunity to launch a war against Byzantium. In 604 AD, King Khusrau II personally led his troops on a campaign, accompanied by a puppet who claimed to be the son of Emperor Maurice, Theodosius, to seize large areas of Armenia, the Mesopotamia, and Syria. Faced with resistance from various regions, the government of Emperor Phocas could only resort to brutal killings to deal with the noble families of the empire. As a result, the more people killed, the more enemies there were. At that time, the situation in the empire could be said to have reached its worst.

This is the situation when Heraclius stepped onto the historical stage. Heraclius, the son of the Governor of Africa, stepped forward at the most appropriate time.
In 608 AD, Heraclius the Elder announced his abandonment of loyalty to Emperor Phocas, as Phocas had overthrown Maurice's throne six years earlier, leading to the outbreak of the Heraclius Uprising. The coins issued by the rebel army showed Heraclius as the consul, although they never declared the title of emperor at that time. Heraclius' eldest nephew Nisitas (son of Heraclius' elder brother Gregory) invaded Egypt by land. In 609, he defeated the general Ponosus of Phocas and defended the province. At the same time, young Heraclius and another force sailed eastward through Sicily and Cyprus. In 609, a rebellion was launched against Phocas, and in the face of despair towards Phocas in various sectors of the country, it received the effect of "raising arms and gathering supporters", quickly gaining support from the Yuan school and the Green Party. The 610 year uprising progressed smoothly and soon arrived in Constantinople.
When he arrived at Constantinople, he established contact with important leaders in the city and planned to overthrow the aristocratic class. They quickly arranged a ceremony, and Heraclius was crowned emperor. When he arrived in the capital, the elite members of the Imperial Guard, also known as the Imperial Guard, surrendered to Heraclius under the leadership of Phocas' son-in-law Priscus. Heraclius entered the city without serious resistance.
When Heraclius captured Phocas, he questioned him, "Despicable person, is this the kind of rule you need?" Phocas replied, "Is it possible that you will rule better in the future?" Suddenly, Heraclius became extremely angry and beheaded Phocas on the spot. Later, he ordered the removal of Phocas' genitals because Phocas had raped Photius' wife. And Fotius is an influential politician in the city.
In the autumn of the same year, Heraclius ascended to the throne and established the Heraclius dynasty.

Forming a family
On October 5, 610, the year after Heraclius' coronation, he married Fabia at St. Stephen's Church at the same time as his coronation and named her Eudoxia. In 612, after her death, Heraclius married her niece Martina. The second marriage is considered incestuous and very unpopular. During the reign of Heraclius' two sons, the current state of division made Martina the center of power and conspiracy. Despite widespread dissatisfaction with Martina staying in Constantinople, Heraclius still brought her to events and refused the request of the elder Sergius to annul the marriage.
Fighting against Persia
The top priority for Heraclius, who had just ascended to the throne, was to resist the invasion of Sassanid Persia. At this time, the Persians had already taken Syria, Palestine, Egypt, Armenia, Iberia, the Mesopotamia, and other places, and invaded the interior of the Byzantine Empire from Asia Minor. In 615, Persian general Shahin captured the city of Karston in the Bosphorus Strait, directly threatening the Byzantine capital Constantinople across the strait. At this moment, the Slavs and Avars began to attack Byzantium from the northwest. The Byzantine Empire was in chaos, and Heraclius was in a difficult situation. He sent an envoy to seek peace with Khusrau, but was rejected.
In response to the crisis, Heraclius began to reform the Byzantine army, dividing the country into several military districts, each of which strengthened its mobile combat and defense capabilities. The church also donated gold and silver to support Heraclius. In 622 AD, he defeated the Sassanid Persian army in the Battle of Issus. Afterwards, he engaged in multiple battles with Persian generals Shahbaz, Shahin, Shapkan, and others, with both sides winning and losing. In the spring of 624 AD, Heraclius led his army to invade the northwest border of the Sassanid Empire, Atropatny, and occupied Ganzak for looting. In 625 AD, Heraclius once again drove to the Caucasus region controlled by Sassanid Persia, using his advantage in the interior to defeat the armies of Shahin and Shapkan one by one, and then launched a surprise attack on the army of Persian general Shahbaz. In the end, all three armies of Persia were defeated, resulting in the loss of tens of thousands of people (Battle of Ariovit). In the same year, Heraclius defeated Shahbaz in the Battle of the Sarus River. In the mid-625 AD, Heraclius had just finished his expedition and led his army back to Cappadocia for rest. At the same time, he also dispatched his confidant Andreas to the north to encourage the Hazars to join the anti Persian war.

The real turning point of the war occurred in 626, when Archmage Sergius broke through the siege of Constantinople by the Avars, causing heavy losses to the Avars as Persian allies (Battle of Constantinople). Heraclius, with the assistance of the Western Turkic Khagan Yahweh and the Khazars, switched from defense to attack, and invaded Iran from Georgia. In 628 AD, Heraclius once again occupied the Persian military stronghold of Ganzak and destroyed one of the most important Zoroastrian fire shrines - the Artur Jushinashp Fire Shrine (Artur Jushinashp Fire Shrine is a shrine dedicated to the worship of Zoroastrian gods by the Persian royal family and warriors, and holds the highest position among fire shrines in Zoroastrianism). Kusilao II hurriedly retreated with the sacred flame. The Byzantine army subsequently defeated Sassanid Persia again in the Assyrian ancient city of Nineveh (Battle of Nineveh) and looted the palace of Dastkaert. Kusilao hurriedly fled to Taixifeng, and the Byzantine army followed suit.
This time it is the turn of Sassanid Persia to face internal and external troubles. The critical situation triggered a palace coup, and Kusilao was thrown into prison. Kavad II (born to Khusrau and Byzantine princess Mary) was proclaimed king. At the end of February 628, according to Kavade's orders, King Khusrau II was killed in prison. In order to consolidate his throne, he killed all his brothers, reportedly a total of 17 people. Soon after, the two countries signed a treaty, and Sassanid Persia withdrew its territory from Edessa to Alexandria. The two countries exchanged prisoners and returned the "True Cross". At this point, the crisis faced by the Byzantine Empire can be said to have come to a temporary end.

Political and religious reform
Military Region System
In the war, Heraclius had already tasted the sweetness of the military district system. After the war, Heraclius still felt pressure from foreign tribes in all directions of the empire, and decided to implement a military district system throughout the country. The military district system was originally implemented in North Africa and Italy, but Heraclius transplanted it to the eastern provinces and established five military districts: Armenia, Opsikin, Kivileodon, Anatolia, and Thrace. His successors continued to improve and promote the scope of the military district system, making it a basic system of the Byzantine Empire. [3]
The essence of the military district system is the integration of local military and political affairs, with local military commanders having administrative jurisdiction and holding two positions, similar to the military governor system in Chinese history. In fact, it puts the whole country under military control. Due to the geographical vulnerability of the Byzantine Empire, war has become a regular function of the state and government, and the military district system is clearly reasonable and necessary for the Byzantine Empire. [3]
Military settlement of farmland
Another important aspect of Heraclius' reform was the establishment of a military garrison system that combined military service with feudal obligations. To address the financial crisis, Heraclius granted the confiscated land and properties of the aristocracy during the war to the officers and soldiers serving in the military as military pay. Land can be inherited or transferred, but the transfer of land requires the transfer of military service obligations to the inheritor. They fought in wartime, cultivated land in peacetime, paid taxes to the government, and were exempt from corv é e. The successors of Heraclius continued to consolidate the military settlement system. This move solved the financial crisis faced at the time and promoted small-scale agriculture, which is considered a key factor in the Byzantine Empire's transition from a slave society to a feudal society. [3]
Church Relations
Chirac's relationship with the church is very delicate. In times of crisis, Heraclius received funding from the church. He adopted measures to mobilize a large number of church assets, using the material and spiritual power of the church to call on the military and civilians across the country to unite against the enemy. But after the war, the church's debt collection caused a conflict between the two sides. In addition, facing the severe situation in the eastern region of the empire, in order to win over the hearts of the people and satisfy the heretics of the "Christological" faction in Egypt and Syria, Heraclius proposed his own "two natures and one will" theory, believing that Christ has two natures but only one will, but it was strongly opposed by the church and abandoned. However, the conflict between Chirac and the Church was still benign and did not develop to the point of destroying the Church through the "Iconoclastic Movement" like Leo III later did. [3]

Heraclius was the first Byzantine emperor to come into contact with Muslims, and according to the Arabs, he was believed to have converted to Islam. He regarded Muhammad as a true prophet and messenger of God. However, other sources suggest that Heraclius may have never read Muhammad's books or received anyone sent by Muhammad.
The evening scenery is desolate
In the same year that Heraclius ascended to the throne, a prophet emerged from the city of Mecca on the Arabian Peninsula, claiming to be the messenger of Allah and spreading the truth to the masses. From then on, the raging flames of Islam rapidly spread in the throat of the world. In the early days, under the spiritual call of Allah, Muslims repeatedly defeated the strong with weakness, almost becoming invincible.
In 633, the newly formed Arab countries turned their war against the Byzantine Empire. That year, the Caliph's army advanced in four directions, attacking Jerusalem, Busra, Damascus, and Homs. Get the support of the 'One Sex Christ' faction in these regions. In 634, the Arab side, with Khalid as its commander, defeated the Byzantine army in Bras, Outer Jordan, and Aichena Dan, Palestine. In 635, Damascus was captured, and Palestine and Syria fell into the hands of the enemy one after another. Heraclius sent his younger brother Theodora to battle and briefly recaptured cities such as Damascus, but suffered a devastating defeat in the Battle of Yarmouk in June, with Theodora killed in battle. Afterwards, the Arabs pursued their victory, and by the time of Heraclius' death in 641, Palestine, Syria, Jordan, and even Egypt had become a vibrant part of the Arab Empire. From then on, the Byzantine Empire had become a country with greatly reduced territory and struggling under the attacks of the Arabs.

Heraclius' greatest achievement was the completion of Hellenistic reforms internally and the recovery of territories occupied by the Persians externally. Militarily implementing the military district system gives local military leaders a certain degree of autonomy and taxation power, increasing their enthusiasm to defend their territory from invasion. Culturally, Heraclius changed the official language of the Roman Empire from Latin to the universal Greek. Change the title of Augustus to Basileus (meaning monarch or emperor in Greek). From then on, Rome completed its Hellenistic transformation, revealing the cultural differences between the Eastern Roman Empire and ancient Rome.

Before his death, he had planned to send envoys to China through the northern route of the Silk Road. Two years after his death, in 643 AD, envoys arrived in Chang'an during the Tang Dynasty, and the Eastern Roman Empire officially established diplomatic relations with the Tang Empire.

The failure in his later years cannot negate Chirac's lifelong struggle. Heraclius undoubtedly had a significant impact on history, which is reflected in two aspects: firstly, he contributed to the survival and extinction of the Eastern Roman Empire (Byzantine Empire). Secondly, the military district system and military settlement system that he laid the foundation for not only became the fundamental system of the Byzantine Empire, but also had a profound impact on the later Ottoman Empire and other Middle Eastern countries. [3]
During the reign of Heraclius, he faced two opponents: the Sassanid Persia was like a sunset before the descent, the Arab Empire was like a fierce tiger at the beginning of the descent, and the Byzantine Empire's one win and one loss were closely related to the strength of their opponents. Setting aside military victories and defeats, the value of Heraclius lies in his role as a pragmatic political reformer, who initially established systems such as military districts and military garrisons, and established the guiding ideology of military establishment. This was absolutely necessary for the survival of the Byzantine Empire, which was surrounded by strong enemies.