This is quite a succinct history of the crusades. For once Wiki gets it just about right.
The 
Crusades were a series of religious wars initiated, supported, and sometimes directed by the 
 in the 
. The best known of these Crusades are those to the 
 in the period between 1095 and 1291 that were intended to recover 
 area from 
. Concurrent military activities in the 
 against the 
 (the 
) and in northern Europe against pagan 
, 
 and 
 peoples (the 
) also became known as crusades. Through the 15th century, other church-sanctioned crusades were fought against heretical Christian sects, against the Byzantine and Ottoman empires, to combat paganism and heresy, and for political reasons. Unsanctioned by the church, 
 of ordinary citizens were also frequent. Beginning with the 
 which resulted in the recovery of Jerusalem in 1099, dozens of Crusades were fought, providing a focal point of European history for centuries. 
In 1095, Pope 
 proclaimed the First Crusade at the 
. He encouraged military support for 
  against the 
 and called for an armed pilgrimage to Jerusalem. Across all social strata in western Europe, there was an enthusiastic popular response. The first Crusaders had a variety of motivations, including religious salvation, satisfying feudal obligations, opportunities for renown, and economic or political advantage. Later crusades were generally conducted by more organized armies, sometimes led by a king. All were granted papal 
. Initial successes established four 
: the 
; the 
; the 
; and the 
. The Crusader presence remained in the region in some form until the 
 in 1291. After this, there were no further crusades to recover the Holy Land.
Proclaimed a crusade in 1123, the struggle between the 
 and 
 in the 
 was called the 
 by Christians, and only ended in 1492 with the fall of the Muslim 
. From 1147, 
 in 
 against pagan tribes were considered crusades. In 1199, 
 began the practice of proclaiming political crusades against Christian 
. In the 13th century, crusading was used against the 
 in 
 and against 
; this practice continued against the 
 in 
 and the 
 in 
 in the 15th century and against 
 in the 16th. From the mid-14th century, crusading rhetoric was used in response to the rise of the 
, only ending in 1699 with the 
.
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