The history of Europe is history of wars. The first historical material relating to European history is "Homeric epic", which tells about Trojan War, followed by "History of Hippo War", "History of Peloponnesian War" and so on. In Middle Ages, largest war that broke out in countries of Europe was Crusade, in which almost all Western European countries were involved. This war ended in failure, but it was a huge victory for evolution of European history. After Eastern Expedition, Europe began to enter gates of modern civilization.First, war caused by religious opposition.
It can be said that Crusades were a religious war that led to a confrontation between entire Islamic world and Christian world. The region around Mediterranean is region of most ancient civilizations and peoples, and conflicts of civilizations are very frequent here. Under such conditions, it is easy to create very stable monotheistic religions such as Judaism, Christianity and Islam, which can strengthen cohesion and vitality of nation. Of course, confrontation between religions is also very fierce, so far religious contradictions in Mediterranean region remain very sharp.
In Hellenistic era, Judaism began to spread in Greece and Rome and gradually merged with Greek culture. During era of Roman Empire, Judaism and Greco-Roman philosophy merged into Christianity. At that time, holy land of Christianity was located in area of Jerusalem. In 7th century, Arab Empire arose, uniting all of Western Asia and North Africa, Jerusalem was also occupied by Islamic troops, and a contradiction began between Islam and Christianity. In addition, Arab Empire also occupied Spanish Peninsula and Sicily, constantly attacking European countries. The contradiction between two worlds began to escalate.
Faced with aggressive impulse of Arab side, Christian peoples of Europe are also resisting. The Spanish Goths retreated to northern border, formed many small countries and launched a "reconquest" that lasted 800 years. The Frankish Charlemagne also repeatedly repulsed attacks of Arabs, captured Barcelona in 801 and founded "Spanish Outskirts". To counter Arab attack, Eastern Rome converted provinces of entire country into military regions, and national system basically entered a state of military control. In period of Leo III, he defeated Arabia with "Greek fire" and curbed expansion of Arabia. It was only after decline of Arab Empire that Eastern Roman Macedonian dynasty regained many of its lost positions.
Eastern Roman Empire
After entering 10th century, situation in Asia and Europe underwent important changes. Some changes took place in Western Europe: firstly, economy of various countries recovered strongly, industry and trade began to flourish, demand for overseas wealth expanded; secondly, dominance of Christianity was basically established in Western Europe. European countries, and Pope received supreme power.; Thirdly, after a long period of chaos, Western European countries now stabilized, and royal power gradually took shape. In Western Asia, Arabs were gradually supplanted by Turks, and they continued to encroach on lands of Eastern Rome. Both sides are capable of unleashing a large-scale war.
And this war is kindled by powder keg of Western Asia-Jerusalem. During era of Arab rule, Jerusalem had to pay more taxes, but in general Christianity was allowed to spread. In 909, Fatimid dynasty was founded, and its sixth Egyptian Fatimid caliph, Hakim, ordered destruction of all Christian churches and synagogues in Jerusalem, including Church of Holy Sepulcher, intensifying persecution of pagans. At same time, Christians who went to Jerusalem for pilgrimage were subjected to robberies and insults by Seljuk Turks. When these disappearances spread to Western Europe, there was an immediate response from various countries. As a result, Western European countries united and launched Eastern Expedition, which lasted 200 years.Secondly, transition from religious wars to economic predatory wars.
In 1095, Pope Urban II established Synod of Clermont in France. At meeting, Pope delivered a lengthy speech calling on Western European Christians to take part in an anti-Islamic crusade for return of "Holy Land". All of a sudden, all sectors of society in Western Europe joined this crazy movement. Many people even believe that participating in Crusades can gain grace of God and forgive sins. However, goals of participating in this war are not same for each class, and they mostly have their own ghosts. The feudal lords tried to plunder wealth from east, Italian merchants tried to replace commercial hegemony of Arabs, church tried to expand its religious reach, and the peasants wanted to get rid of poverty and go east to east. find a happy land...
In 1096, impatient crusaders from Peasants' Army marched first, but entire army was destroyed. In autumn of same year, a well-armed knightly crusader, representing a regular army, set out. They invaded Western Asia in second year, after unreasonable burnings, murders and robberies, they founded Kingdom of Jerusalem here, promulgated "Jerusalem Rules" and transplanted feudal system of Western Europe into Western Asia. To strengthen power in country, Pope established three main knightly orders: Templar, Hospital and Teutonic. Like a standing army in Jerusalem. To reduce pressure of Seljuk Turks on Jerusalem, crusaders also helped Eastern Rome to return peninsula of Asia Minor. We can say that first Eastern expedition was a success: the Kingdom of Jerusalem founded by them existed in Western Asia for 88 years.
In 1144, Seljuk Turks occupied Edessa, so Europe carried out a second Eastern expedition led by Louis VII of France and Conrad III, emperor of "Holy Roman Empire". But both armies were defeated. In 1189, Western Europe launched a third Eastern expedition. The leaders of this expedition were Red-bearded Frederick I of Holy Roman Empire, Philip II of France and Richard I of England. The German emperor drowned while crossing Salev River, and part of it fell apart; France occupied Sicily and later occupied port of Accra (Acre) and returned to France with part of crusaders in 1191. Only British army was successful and British king captured Cyprus and established Kingdom of Cyprus, which was later sold to Jerusalem. In 1192, crusaders signed a treaty with Egypt, dividing spheres of influence between two parties.
Starting with fourth Eastern Expedition, nature of Eastern Expedition began to undergo tremendous changes. During first three Eastern expeditions, Eastern Rome tried its best to cooperate. However, crusades seriously undermined ruling system of Eastern Rome and exacerbated contradictions between Orthodox Church and Christian world. In 1202, Pope Innocent III launched fourth Eastern Crusade, purpose of which was occupation of Egypt. However, Crusaders did not have means to cross sea. At instigation of Venetian nobility, crusaders turned to attack Constantinople. Of course, crusaders heeded their words and captured Byzantium, burned, killed and robbed here for up to 3 days, and Venice took opportunity to occupy most of land along Aegean Sea. Later, Crusaders founded Latin Empire in Byzantium.
The crusaders attacked their compatriots, and their nature of plundering wealth was exposed. This incident reminds people of Mycenaean era, when Greek coalition forces attacked Troy. After that, Europe launched five more eastern expeditions, but they all quickly failed. In these eastern expeditions, crusaders almost always plundered all way, and hypocrisy of pope was completely exposed. In 1271, Edward of England led Ninth Eastern Expedition, but in order to return to China as soon as possible to inherit throne, Western European countries could no longer start Eastern Expedition. In 1291, last stronghold of Acre was captured by Egypt, and Kingdom of Jerusalem perished. The Crusades were declared a failure.Three who are winner of crusades
Although Crusades ended in failure, their impact on Western Asia and Europe was enormous. First, we can see who lost most in crusades. Although this war had a huge impact on Islamic world, it did not shake Islamic dominance in Western Asia, so there were no losers in Western Asia. For Western European countries, although they suffered many setbacks, they did not threaten rule itself or cause economic destruction, so they were not biggest losers. But initiator of war lost most - Pope, and in middle Eastern Roman Empire.
Before Eastern Expedition, Pope held supreme power in Europe, and everything was ruled by Christian theocracy. However, failure of Eastern Expedition raised prestige of Church, and Pope's prestige continued to decline; during Eastern Expedition, greed and tyranny of crusades no doubt caused many Europeans to question their faith in Catholicism; Christian fanatics have greatly weakened support of pope.
In contrast to decline of Pope's power, royal power in Europe began to rise. In 1301, King Philip IV of France imprisoned French archbishop, and two years later broke into pope's residence and beat him. The Pope was stricken with humiliation and soon died. For next 70 years, France was ruled by Pope, known to history as "Prisoner of Avignon". This incident shows that royal power in Europe began to defeat religious power.
Another big loser was Eastern Roman Empire. After encounter with Fourth Crusade, ancient Eastern Rome actually existed in name only. In 1261, with help of Genoa, Eastern Rome was restored and Paleolio dynasty (1261-1453) was established. After that, Byzantium barely held its rule for 200 years, but its territory was mostly limited to city of Byzantium. The decline of Eastern Rome created conditions for rise of Turks. In 14th century, Ottomans rebelled and continued to attack Byzantium. In 1453, Ottomans captured Byzantium, Constantinople was renamed Istanbul and became capital of Ottoman Turkish Empire. The crusaders failed in their goal of suppressing Islam, but instead they weakened their compatriots, leading to rise of Turkey and fall of all of southeastern Europe.
Italy was biggest winner of Crusades. Economically, cities of northern Italy replaced Byzantium with a monopoly on trade and became a transit point for trade between East and West. Since then, Italy has been rapidly moving towards prosperity, and capitalist economy has begun to rise. In 1407, world's first bank was founded in Venice. Culturally, a large number of documents from Constantinople poured into Italy, broadening horizons of Italians. The Italians began to look for ancient Roman culture, which contributed to emergence of Renaissance. In 1088, Italy founded earliest university in Europe, University of Bologna, which later became famous for studying Encyclopedia of Civil Law in Eastern Rome.
In terms of all historical development, Europe is winner. After this war, royal power of European countries rose, which contributed to formation of nation-states, a large number of Eastern inventions were brought to Europe, accelerating progress of European technology. So compass, gunpowder and printing were brought to countries of Western Europe. Western Europeans learned about prosperity of Western Asia, and people began to yearn for East, one of manifestations of which is wide distribution of Travels of Marco Polo. This has become an important reason for Europeans to open new routes.
However, in general, confrontation between Christian world and Islamic world did not end there. In this kind of confrontation, Spain and Portugal acted independently and became leaders in opening of new sea routes; Austria continued to obstruct advance of Ottoman Empire into southeastern Europe and finally formed stronghold of Catholic Church - Habsburg dynasty. .Conclusion
At same time as Crusades, Mongol conquest took place. The conquest of Mongolia destroyed one by one ancient Asian civilizations and brought many agricultural civilizations to a halt. The Crusades greatly accelerated progress of coastal civilized countries. Although these two wars took place at same time, they did not overlap with each other, if you add up two wars, they would actually cover entire Eurasian continent and North Africa. A watershed in development of East and West may appear here.