Verified answer

here is a nice article on THE CRUSADES :

The Crusades

Proud knights in the Crusades would march towards forgiveness of their sins, filled with greed. Bloodshed, they believed, was worth it, dying was worth it. Marching towards Jerusalem with victory in their eyes, they would take anyone who stood in their way of victory. That was the Crusades of the Middle Ages.

In the year 1095, people were shocked in Western Europe by the words of Pope Urban II, "The Muslims have conquered Jerusalem". Pope Urban wanted the Christians to retake Jerusalem from the Muslims. People shouted "God wills it". All over France these were the warring words of the Christians.

The French, German, and Italians were the European Christians that went on Crusades. The word Crusade meant "a war of the cross". During the first Crusade (1095-1097) most of the knights died of hunger, thirst or disease. When they got to Jerusalem they slaughtered anyone they could find. They took vows before going on a crusade. Sometimes during a crusade a knight would forget his vows and ride off or live in the village closest by.

In a Crusade there were pilgrims who were going to pray in Jerusalem, groomers that cleaned the horses, wives and children of the knights, and two kinds of knights: a mounted knight who rode on a horse and a foot soldier who walked on foot. Some of the knights went on Crusades to get rich or to steal a new home from the people they were fighting, but most of the knights went to get healed of their sins. Richard the Lion Heart (or Richard the I of England) was a famous general in the Crusades. The fourth Crusade (1199-1204) started off with a tournament against the Turks in France but the Crusade ended in tragedy. Most of the armies that went were already half destroyed by the Turks. They didn't reach Jerusalem. All together there were six Crusades in a period of 176 years. The Crusades lasted from 1095 until 1271.

When the knights were attacked in a Crusade they used huge siege weapons. The ballista was the simplest weapon. It was like a giant crossbow that could shoot arrows a distance of 350-450 yards in length. The mangonel was called a wild donkey by the Romans. It was a medium range catapult. The trebuchet was the most powerful siege weapon. It was a catapult that could fling rocks long range. A battering ram was a log cut from a heavy tree. The battering ram got its name because the Romans said it looked like a ram. It was then tied onto a penthouse to protect the knight from arrows and it took twelve men to swing it. All these siege weapons were used to get into Jerusalem by the knights of the Crusades. Other knights would try to dig under ground and then set fire to the wall supports underground in hopes that the wall would collapse. Another way knights tried to get into Jerusalem was to put long ladders against the wall and trying to climb them without being pushed over or having boiling liquids poured onto them, or being killed by a knight on the wall. The knights also built huge staircases, called siege towers, that were pushed against the wall and the knights walked up the staircases. When they actually reached Jerusalem however, they waited awhile before attacking to starve their enemy, but it didn't work so they just attacked. The knights captured towers built on the walls. When the knights got inside the walls of Jerusalem they killed people walking street or inside buildings.

Religion was important to the knights in the Middle Ages. One of the results of the Crusades was the founding of new Christian religious orders. Most of the monks were former knights who fought against each other in the Crusades. The knights did capture Jerusalem for a short period of time, but the Muslims kept on re-taking Jerusalem. The knights gained temporary power, but lost many soldiers during the deadly Crusades, not to mention causing the death of many innocent Muslims. The Crusades is a violent reminder of the greed of Middle Ages.

=======================

more info:

http://en.wikipedia.org/wiki/Crusade

Crusades were a series of actions advancing a principle or tending toward a particular end.