The Middle English equivalents were derived from Old French; croiserie in the 13th–15th centuries and croisée in the 15–17th century. 1575, and continued to be the leading form until c. Although the term "Crusade" has been adopted by historians to describe the Christian holy wars from 1095, the range of events to which it has been applied is so great that its use can create a misleading impression of coherence, particularly regarding the early Crusades.The Crusades in the Holy Land are traditionally counted as nine distinct campaigns, numbered from the First Crusade of 1095–99 to the Ninth Crusade of 1271–72.
The Islamic prophet Muhammad founded Islam in the Arabian Peninsula and had united much of Arabia into a single polity by his death in 632.
Arab power expanded rapidly in the 7th and 8th centuries largely by military conquest.
However, the Crusades had a profound impact on Western civilisation: they reopened the Mediterranean to commerce and travel (enabling Genoa and Venice to flourish); they consolidated the collective identity of the Latin Church under papal leadership; and they constituted a wellspring for accounts of heroism, chivalry, and piety that galvanised medieval romance, philosophy, and literature.
The Crusades also reinforced the connection between Western Christendom, feudalism, and militarism.
The initial success of the Crusade established the first four Crusader states in the Eastern Mediterranean: the County of Edessa, the Principality of Antioch, the Kingdom of Jerusalem and the County of Tripoli.
The enthusiastic response to Urban's preaching from all classes in Western Europe established a precedent for other Crusades.
The rise of the Ottoman Empire in the late 14th-century prompted a Catholic response which led to further defeats at Nicopolis in 1396 and Varna in 1444.
Catholic Europe was in chaos and the final pivot of Christian–Islamic relations was marked by two seismic events: the fall of Constantinople to the Ottomans in 1453 and a final conclusive victory for the Spanish over the Moors with the conquest of Granada in 1492.
When Urban began preaching for the first campaign the word "Crusade" did not exist: instead, the terms iter, for journey, or peregrinatio, for pilgrimage, were used.