The siege of Akko was one of the most important military events of the Third Crusade and probably lasted from August 1189 to July 1191. The immediate cause of the Third Crusade was the great successes of the Muslim army in the battles with Christians, especially the defeat of the King of Jerusalem, Gwidon de Lusignan at Hattin in 1187 and the subsequent seizure of Jerusalem by the troops of the great Muslim leader Saladin. It was primarily the conquest of Jerusalem that led to the organization of the Third Crusade by the German Emperor Frederick Barbarossa, which aimed to recapture this holy city from the hands of the infidels. However, the German authorities drowned during their march to the Holy Land, and the crusade began to suffer from a conflict between its two chiefs: King Richard the Lionheart and King Philip August of France. The siege of Akka began with the actions led by the loser from Hattin - Gwidon de Lusignan, to whom from September / October 1189 crusader troops began to arrive. However, it was not until 1191 that the main forces of the Crusaders, led by the feuding kings of England and France, arrived at Akka. It is assumed that at the beginning of the summer of 1191, the army of the Crusaders numbered about 25,000. people, and the Muslim army - probably a similar number of soldiers. However, there are only estimates and there is a risk of error. The decisive assault of the crusaders on the city took place in July 1191, which led to the surrender of the Muslim Akka crew. It is often assumed that the siege of Akka was one of the longest and bloodiest in the history of the Crusades, and perhaps of the entire Middle Ages.
It is quite commonly assumed that the initiator of the crusades (i.e. the crusades) to the Holy Land was Pope Urban II, who at the Synod in Clermont in 1095 threw the slogan of her liberation from the hands of the infidels. As a result of a combination of various social, economic and religious reasons, this slogan fell on a very fertile ground in Latin Europe and became the cause of the first knight's crusade in the years 1096-1099. As a result of this crusade, not only was Jerusalem conquered, but also in 1100 the Kingdom of Jerusalem was established in the Middle East. Its first king was Baldwin I, although the actual "founder" of the new state was Geoffrey of Bouillon. After the first crusade, there were others, of which we can mention the third (1189-1192) or the fourth (1202-1204), which, however, did not reach the Holy Land, and led to the sacking of Constantinople by would-be crusaders. It is assumed that the end of the crusade movement to the Holy Land is the year 1291, which is the same as the conquest of the last Crusader stronghold in these areas, i.e. Akki. The importance of the crusades in the history of medieval Europe and in the history of its military was enormous. First of all, they led to a significant weakening of the Byzantine Empire, and indirectly facilitated the later expansion of the Ottoman Turks in the 14th-15th centuries. They led to a great increase in the role of Italian cities in the Levantine trade and the development of boatbuilding in the Apennine. The intellectual horizons of contemporary Europeans widened considerably. For the defense of the Holy Land, knightly orders were also established, including the Teutonic Order.