Military history of the Crusader states
The Seljuk–Crusader War began when the First Crusade wrested territory from the Seljuk Turks during the Siege of Nicaea in 1097 and lasted until 1128 when Zengi became atabeg of Aleppo. At the latter date, the chief threat to the Crusaders from the east and north became the Zengids. The conflict was generally fought between European Crusaders and the Seljuk Turks and their vassals. The Muslim Syrian emirates occasionally allied themselves with the Christians against rival states.
Children's Crusade
In the first movement, Nicholas, an eloquent shepherd from the Rhineland in Germany, tried to lead a group across the Alps and into Italy in the early spring of 1212. Nicholas said that the sea would dry up before them and allow his followers to cross into the Holy Land. Rather than intending to fight the Saracens, he said that the Muslim kingdoms would be defeated when their citizens converted to Catholicism. His disciples went off to preach the call for the "Crusade" across the German lands, and they massed in Cologne after a few weeks. Splitting into two groups, the crowds took different roads through Switzerland. Two out of every three people on the journey died, while many others returned to their homes. About 7,047 arrived in Genoa in late August. They immediately marched to the harbor, expecting the sea to divide before them; when it did not many became bitterly disappointed. A few accused Nicholas of betraying them, while others settled down to wait for God to change his mind, since they believed that it was unthinkable he would not eventually do so. The Genovese authorities were impressed by the little band, and they offered citizenship to those who wished to settle in their city. Most of the would-be Crusaders took up this opportunity. Nicholas refused to say he was defeated and traveled to Pisa, his movement continuing to break up along the way. He and a few loyal followers continued to the Papal States, where they met Pope Innocent III. The remaining ones departed for Germany after the Pontiff exhorted them to be good and to return home to their families. Nicholas did not survive the second attempt across the Alps; back home his father was arrested and hanged under pressure from angry families whose relatives had perished while following the child.