전쟁사 좋아하는 사람 모여라~~

How would the course of the Imjin War have changed if Ming's reinforcement troops had not been sent?

The Arab-Byzantine Wars were not a conflict that ended with a single battle or treaty, but a long-term clash that spanned several centuries from the 7th century onwards. Early Arab conquests led to the loss of Syria, Palestine, and Egypt for Byzantium, causing significant changes to the empire's economy and administrative system. However, by successfully defending Constantinople, the empire was able to reorganize its survival base centered around Anatolia and the Balkans. While the 8th and 9th centuries saw protracted warfare along the borders, the 10th century marked a Byzantine counter-offensive, reclaiming key eastern strongholds like Antioch. The Arab world also underwent political restructuring with the succession of the Umayyad and Abbasid caliphates and the rise of regional powers. The wars cannot be explained solely by religion; competition over territory, taxes, trade routes, and strategic locations played a complex role. After prolonged conflict, Byzantium could not fully return to its former status as a Mediterranean empire, but it managed to protect its capital and core regions. This process set the stage for the later emergence of the Seljuk Turks and new eastern wars for Byzantium.

In the late 10th century, the Byzantine Empire leveraged the fragmentation of Arab powers and shifts in border defense to expand its influence in Syria and Cilicia. Nikephoros II Phokas sought to regain the initiative on the eastern front through military reforms and campaigns, securing the crucial stronghold of Antioch in 969. His successor, John I Tzimiskes, continued expeditions towards Syria in the 970s, advancing Byzantine forces to a position capable of threatening Damascus and Jerusalem. However, the empire did not permanently control all cities in the region, requiring ongoing warfare and negotiation with local powers. The Byzantine counteroffensive succeeded in reclaiming some territories lost in the 7th century and pushing the border southward. Yet, the empire simultaneously had to contend with issues in Bulgaria and the Balkans, placing a significant burden on maintaining its eastern gains. Later, in the 11th century, the Seljuk Turks, advancing westward from Central Asia, emerged as a new threat, prompting further changes in Byzantine eastern policy.

Starting in the mid-9th century, the Byzantine Empire began a full-scale counteroffensive against Arab forces. In 863, the Byzantines repelled an Arab invasion at the Battle of Lalakaon, a victory that marked a shift from border defense to offensive operations. As the empire's military strength and finances gradually recovered, expeditions beyond the Anatolian border into enemy territory increased. In the 10th century, Nikephoros II Phokas led military expansion, successively capturing key strongholds in Cilicia and northern Syria. In 969, Antioch was taken, extending Byzantine influence back into northern Syria. John I Tzimiskes continued these eastern campaigns, further solidifying the empire's position. However, this process was not merely about reclaiming territory. Defending newly acquired regions required sustained investment in troops and finances, as well as managing relationships with local political factions. Nevertheless, Byzantium recovered to a point where it could directly threaten major Arab strongholds, a stark contrast to its previously defensive posture.

Even after the fall of the Umayyad Caliphate in 750 and the rise of the Abbasid Dynasty, clashes between the Byzantines and Arab forces continued. Both sides repeatedly launched military expeditions in the border regions of eastern and southern Anatolia, attacking enemy fortresses and cities, or capturing prisoners and spoils of war. The Byzantine army defended using mountainous terrain and fortifications, while the Arab forces frequently conducted raids that advanced rapidly across the border before retreating. These wars were characterized by attrition over control of the border and military initiative, rather than one side completely conquering the other. Internal Byzantine conflicts, such as the Iconoclasm controversy and political strife, also occurred, but the border defense system played a crucial role in the empire's long-term resistance. Entering the 9th century, internal divisions within the Abbasid Caliphate and the growth of regional powers made it difficult to maintain consistent pressure, and the Byzantines gradually gained opportunities for counteroffensives. The prolonged conflict burdened both sides, but the Byzantine preservation of key Anatolian territories laid the foundation for their subsequent military recovery.

In the early 8th century, Arab forces, under the rule of the Umayyad Caliphate, expanded their territory and intensified pressure on the Byzantine Empire. In 717, a large army led by Maslama ibn Abd al-Malik besieged Constantinople. Emperor Leo III at the time organized the capital's defenses and prepared for the assault. The Byzantines utilized their formidable walls and navy, employing Greek fire to inflict significant damage on the Arab fleet. Compounding the situation, harsh winter conditions, food shortages, and disease worsened the besiegers' plight. Attacks from Bulgarian forces also added to the Arab army's burden. In 718, the Arab forces lifted the siege and retreated, marking another failure in their plan to conquer Byzantium by capturing its capital. This battle was significant as it bought the Byzantines crucial time to hold their ground in Anatolia and the Balkans. Meanwhile, the Umayyad Caliphate also expended considerable resources on the prolonged campaign. While the successful defense of the capital didn't mean Byzantium recovered its lost territories, it was an event that thwarted a large-scale attack threatening the empire's very existence.

The Arab forces, having conquered Syria and Egypt, began to threaten the Byzantine Empire's capital, Constantinople. In the late 7th century, Arab armies repeatedly attacked Asia Minor and exerted pressure on the seas surrounding the capital using their navy. The siege and naval assault, which lasted from 674 to 678, is traditionally known as the First Siege of Constantinople. The Byzantines defended their capital using the formidable land walls and their navy, with Greek fire playing a crucial role in attacking enemy ships. Despite the prolonged campaign, the Arab forces failed to capture the capital and faced difficulties with supplies and troop maintenance. The siege ultimately ended with the Arab withdrawal, and the Byzantines successfully defended the heart of their empire. While this victory did not result in the recovery of the lost territories of Syria and Egypt, it demonstrated that Arab power could not instantaneously collapse the entire empire. The survival of Constantinople provided a foundation for the Byzantines to continue their resistance in the Balkans and Asia Minor.

Egypt was a crucial region supplying grain and taxes to the Eastern Roman Empire, and also a strategic hub connecting the eastern Mediterranean. However, when Arab forces advanced into Egypt in 639, the empire's southern defenses rapidly crumbled. Under the command of Amr ibn al-As, the Arab army pushed along the Nile River, and by 641, Alexandria, a major city in Egypt, fell. Although the Eastern Romans temporarily recaptured Alexandria in 645, they lost it again due to the Arab counterattack. The conquest of Egypt provided the Arab forces with immense revenue and food, and also laid the groundwork for their subsequent expansion into North Africa. The Eastern Roman Empire could no longer sustain its economic and military strength in the eastern Mediterranean through Egypt. The focus of the war shifted not only to land borders but also to the sea, and both sides began a new competition for the ports and islands of the eastern Mediterranean. The loss of Egypt was a significant turning point, marking the rise of Arab power from a regional force to a major player in the Mediterranean world.

As the Arab conquest of Syria progressed, the Eastern Roman Empire successively lost key strongholds in the Levant. Following the defeat of the Eastern Roman army at the Battle of Ajnadayn in 634, the defensive lines in Palestine and southern Syria faltered, and Damascus fell in 635. Emperor Heraclius of the Eastern Roman Empire gathered forces to attempt a counterattack, but suffered a decisive defeat against the Arab army at the Battle of Yarmouk in 636. After this battle, the Eastern Roman Empire effectively abandoned Syria and retreated northward. Jerusalem also fell to Arab forces in 638, and the Arab army then advanced towards Egypt. The Egyptian campaign, which began in 639, put pressure on defensive strongholds along the Nile River, and Alexandria was captured in 641. As Egypt was a crucial granary and source of revenue for the Eastern Roman Empire, its loss was more than just a territorial defeat; it dealt a significant blow to the empire's economic foundation. Ultimately, by the mid-7th century, the center of the Eastern Roman Empire rapidly shifted from Syria and Egypt to Anatolia.

Immediately after Heraclius concluded his war with Persia, the Arab invasion began. Under the rule of Caliphs Abu Bakr and Umar, the Islamic forces rapidly advanced beyond the Arabian Peninsula into Syria and Palestine. The Eastern Roman army resisted using border fortresses, but they were short on troops in many areas, and some local residents were dissatisfied with the central government's high taxes and religious policies. The defeat of the Eastern Roman army at the Battle of Ajnadayn in 634 shook the defenses of Syria, and the Battle of Yarmouk in 636 became a decisive turning point. Although the Eastern Roman army deployed a large force, they were defeated by the mobility and command of the Arab army. After Yarmouk, the Eastern Roman Empire found it difficult to hold onto most of Syria and had to focus on defending the capital, Constantinople, and Anatolia. This war fundamentally changed the Eastern Roman Empire's territory and strategy.