The Crusades were a series of religiously
sanctioned military campaigns waged by much of Roman Catholic Europe,
particularly the Franks of France and the Holy Roman Empire. The specific
crusades to restore Christian control of the Holy Land were fought over a period
of nearly 200 years, between 1095 and 1291. Other campaigns in Spain and Eastern
Europe continued into the 15th century.
The Crusades were fought mainly by Roman Catholic
forces (taking place after the East-West Schism and mostly before the Protestant
Reformation) against Muslims who had occupied the near east since the time of
the Rashidun Caliphate, although campaigns were also waged against pagan Slavs,
pagan Balts, Jews, Russian and Greek Orthodox Christians, Mongols, Cathars,
Hussites, Waldensians, Old Prussians, and political enemies of the various
popes. Orthodox Christians also took part in fighting against Islamic forces in
some Crusades. Crusaders took vows and were granted penance for past sins, often
called an indulgence.
The Crusades originally had the goal of recapturing Jerusalem and the Holy Land
from Muslim rule and their campaigns were launched in response to a call from
the Christian Byzantine Empire for help against the expansion of the Muslim
Seljuk Turks into Anatolia. The term is also used to describe contemporaneous
and subsequent campaigns conducted through to the 16th century in territories
outside the Levant usually against pagans, heretics, and peoples under the ban
of excommunication for a mixture of religious, economic, and political reasons.
Rivalries among both Christian and Muslim powers led also to alliances between
religious factions against their opponents, such as the Christian alliance with
the Sultanate of Rum during the Fifth Crusade.
The Crusades had far-reaching political, economic, and social impacts, some of
which have lasted into contemporary times. Because of internal conflicts among
Christian kingdoms and political powers, some of the crusade expeditions were
diverted from their original aim, such as the Fourth Crusade, which resulted in
the sack of Christian Constantinople and the partition of the Byzantine Empire
between Venice and the Crusaders. The Sixth Crusade was the first crusade to set
sail without the official blessing of the Pope. The Seventh, Eighth and Ninth
Crusades resulted in Mamluk and Hafsid victories, as the Ninth Crusade marked
the end of the Crusades in the Middle East.