1. The conquest of Constantinople(1204) by occurred in April 1204 and marked the climax of the Fourth Crusade. Mutinous Crusader armies captured, looted, and destroyed parts of Constantinople, the capital of the Byzantine Empire. After the capture of the city, the Latin Empire (known to the Byzantines as the Frankokratia or the Latin Occupation) was established.
2. Siege of Nicaea - The Siege of Nicaea took place from May 14 to June 19, 1097, during the First Crusade. They defeated the Turkish defenders and sacked the city May 21, 1097. Byzantine Emperor Alexios I had instructed Boutoumites to secretly negotiate the surrender of the city without the crusaders' knowledge
3. The Fall of Constantinople- The Fall of Constantinople took place 1453, at the time one of the most heavily fortified cities in the world. Constantinople was taken over by Ottoman Turks, led by their leader Sultan Mehmed II. This led to the creation of the Ottoman Empire and marked the end of the Byzantine Empire, a continuation of the Roman Empire, an imperial state dating back to 27 CE, which had lasted 1500 years .
4. Pope Urban II calls for the first crusade -On Nov. 27, 1095, giving one of the most influential speeches of the Middle Ages, Pope Urban II calls for the first crusade. He calls all Christians in Europe to war against Muslims in order to reclaim the Holy Land, with a cry of “Deus vult!” or “God wills it!”
5. The Siege of Damascus- The Siege of Damascus took place in 1148 during the second crusade. It ended in a decisive crusader defeat and led to the failure of the crusade. The two main Christian forces that marched to the Holy Land in response to Pope Eugene III and Bernard of Clairvaux's call for the Second Crusade were French and German forces. Both faced disastrous marches across Anatolia in the months that followed, with most of their armies being demolished. The original focus of the crusade was Edessa (Urfa), but in Jerusalem, the preferred target of King Baldwin III and the Knights Templar was Damascus. At the Council of Acre, magnates from France, Germany, and the Kingdom of Jerusalem decided to divert the crusade to Damascus.
6. The Sixth Crusade - The Sixth Crusade started in 1228 as an attempt to regain Jerusalem. It began seven years after the failure of the Fifth Crusade and involved very little actual fighting. The diplomatic maneuvering of the Holy Roman Emperor Frederick II, resulted in the Kingdom of Jerusalem regaining some control over Jerusalem for much of the ensuing fifteen years as well as over other areas of the Holy Land.
7. Siege of Acre - The Siege of Acre took place in 1291 and ended in a Crusader defeat, which resulted in Turkish invaders controlling once Crusader-controlled Acre. Although the crusades continued for several more centuries, the capture of Acre marked the end of further crusades to the Levant. When the city fell to the Turks, the Crusaders lost their last major territorial hold of the Crusader Kingdom of Jerusalem.
8. The third crusade - The Third Crusade, which occurred during 1189 to 1192, was an attempt by European Christian leaders to reconquer the Holy Land following the capture of Jerusalem by the Ayyubid Sultanate in 1187. The crusade was largely triumphant in capturing the important cities of Acre and Jaffa for the Crusader Kingdom of Jerusalem, regaining most Ayyubid controlled territories, but the crusade failed to re-capture Jerusalem, the main objective of the crusade.
9. The Battle of Hattin - The Battle of Hattin took place in 1187 during the second crusade, between the crusaders and the forces of the Ayyubid Sultanate. The Muslim armies under Saladin demolished the Crusader forces, removing their potential to wage war. As a direct result of the battle, Muslims became the dominant military power in the Holy Land once again, re-conquering Jerusalem and most Crusader-held cities. This battle led to the Third Crusade.
10. The Siege of Edessa - The Siege of Edessa took place in 1144, before the start of the second crusade,resulting in the fall of a important capital crusader city of Edessa to Zengi, a turkish ruler of Mosul and Aleppo, located in modern-day Syria. This event sparked the start of the Second Crusade.