A crusade, in the primary sense of the word, is a military expedition undertaken from religious motives and/or with a religious purpose. A person who goes on a crusade is a crusader, and the verb ‘to crusade’ means ‘to go on a crusade’.
Unless otherwise indicated, the expression ‘the Crusades’ will almost certainly refer, more specifically, to the campaigns undertaken by some of the Christian states of Europe from the 11th to the 13th centuries with the aim of driving the Muslim invaders out of the Holy Land (i.e., roughly the territory of the modern states of Israel, Palestine, and Jordan, together with parts of Lebanon and Syria).
- The First Crusade was undertaken in response to an appeal by Pope Urban II (1035-1099, Pope 1088-1099) to ensure that Christian pilgrims had access to the Christian holy sites. It lasted from 1095 to 1099 and resulted in the capture of Jerusalem in 1099 and the establishment of four Crusader States in the Holy Land (namely, the Kingdom of Jerusalem, the Principality of Antioch, the County of Tripoli, and the County of Edessa). However, much of the territory secured in the First Crusade was soon lost, and the crusades which followed, in the 12th and 13th centuries, were attempts to regain this lost territory. The Second Crusade, from 1147-1149, was a response to the Turkish conquest of the State of Edessa in 1146 and was unsuccessful. The aim of the Third Crusade, the so-called King’s Crusade, led by King Richard I of England (1157-1199, reigned 1188-1199) and King Philip II of France (1165-1223, reigned 1179-1223), and lasting from 1187 to 1192, was to recover Jerusalem, which had fallen to the Sultan Saladin (1137-1193, reigned 1174-1193) in 1187: it recaptured the cities of Acre and Jaffa but failed to take back Jerusalem The Fourth Crusade, under Pope Innocent III (1160-1216, Pope 1198-1216), set out for Jerusalem in 1202 but never reached the Holy Land: the crusaders became involved in the internal affairs of the Byzantine capital, Constantinople, which led to their conquest and sack of the city in 1204. The remaining five crusades, between 1217 and 1272, were on a small scale, and all were unsuccessful.
- The Children’s Crusade: according to tradition, in 1212 a band of many thousands of children, under the joint leadership of two boys, one French, one German, set out for the Holy Land to convert the Muslims to Christianity. Their fate is not known: it is assumed that many died on the journey to the Mediterranean coast, where those who remained either abandoned the crusade or were deceived into boarding ships which took them to a life of slavery in North Africa. Parts of this traditional account are based on historical events. In Germany in 1212 a shepherd, Nicholas of Cologne, attracted 30,000 followers who vowed to join him in a crusade and whom he led across the Alps to Genoa in the expectation that the sea would divide and allow them to walk to the Holy Land. And in the same year in France a 12-year old shepherd, Stephen of Cloyes, led his thousands of followers, many of them very young, as far as Marseilles on what was intended to be the first stage of a crusade to the Holy Land.
As well as the crusades to the Middle East in the 11th, 12th, and 13th centuries, there have, of course, been many other crusades, i.e., military expeditions undertaken, e.g., to conquer a nation and convert its inhabitants to Christianity, or to win back territory which has fallen into non-Christian hands. There were, e.g., the Northern Crusades, (more specifically, the Wendish, Swedish, Livonian, and Prussian Crusades) fought between 1147 and 1410 in the area around the Baltic Sea, to bring Christianity to the inhabitants of this region; and the Spanish Crusades, fought between 711 and 1491, to drive the Muslim invaders out of Spain (the so-called Reconquista).
Nowadays the word crusade (with no initial capital) is most commonly used, sometimes ironically, in reference to (long and vigorous) campaigns of a non-military nature which are undertaken to secure (what is believed to be) a morally worthwhile end. Thus a powerful campaign to promote awareness of environmental issues or to encourage reading for pleasure among children might well be spoken of as a crusade; Mrs. Whitehouse (Constance Mary Whitehouse (1910-2001)) regularly described her Clean Up TV Campaign (against sexual scenes on television) as a crusade; and the evangelical campaigns in which the American evangelist Billy Graham (William Franklin Graham, 1918-2018) sought converts to Christianity by preaching before large indoor and outdoor rallies were known as crusades.
- Etymological note: Crusade comes from the French croisade (‘crusade’), which derives, through old French crois, from Latin crux, ‘cross’. The word, in various forms, e.g. croisad,crossiade, croisada, cruysado and crusada, signified the wearing by crusaders of a badge commemorating the crucifixion of Jesus Christ. Crusaders were commonly said to 'have taken the Cross' - to have adopted the badge and joined the crusading army.