The Normans' mercenary and crusading activities in the Eastern Mediterranean is recounted by the 11th century historian William of Apulia's account of The Deeds of Robert of Guiscard.  The Deeds of Robert Guiscard is a long epic about the heroic deeds of the Normans in Italy and Byzantium from around 1015 to 1085 AD.  The Normans began  hiring themselves as mercenaries to aid the Byzantines against the rising power of the Seljuq Turks who had defeated the Byzantines at the Battle of Manzikert in 1071 in Anatolia. In the course of the battle, the Emperor Romanus IV Diogenes was captured.

European / Turkic / Mediterranean Rivalries and the Crusades

From the 11th century onward, Europeans sought greater access to the Eastern European and Mediterranean based trade and commerce.  The Crusades against the Islamic states of the Near East and Spain, and against pagan regions of Northern Europe and Russia were products of Western Europe's  inferior trade position.  They relied upon an ideological religious crusade to mobilize a profit-seeking military aristocracy in alliance with the clergy.  The accumulation of wealth among this aristocracy and clergy rested on their ability to disenfranchise and dislocate peasants from land-based rights privileges during the late phases of the 10th century onward.  While peasants were not passive and would at various times rebel against this encroachment, the trend toward lordship and prominent clerical estates as major landowners in Europe became the major force of accrual of wealth and prestige in late medieval and early modern Europe.  For recent surveys of this trend toward peasant dislocation and the rise of the aristocratic court, military orders and clergy, see Chris Wickham, The Formation of the Early Middle Ages (Oxford, 2005), and The Inheritance of Rome:  Illuminating the Dark Ages 400-1000 (Viking, 2009), and M. McCormick, The Origins of the European Economy (Oxford, 2001).

Normans in Sicily and Italy

Pope Urban II's call for a Crusade also intersected with the occupation of Southern Italy and Sicily by the Normans.  As a French Pope he was dependent on Norman and French support for stay in office and to deflect the threat of anti-popes that could be created at the whim of the emperors.

Bohemond and the Norman Crusaders

Bohemond (1058-1111) was the son of Robert Guiscard, the Norman conqueror of Italy. As the eldest son he was crowned Prince of the southern Italian port town of Taranto.  In the late 1090s he led a military expeditionary force to Anatolia and the lands of the Byzantine empire that were then under assault by the Seljuk Turks.  When he arrived in Constantinople his imposing physical presence and leadership made such an imposing presence that the young Byzantine princess,  Anna Comnena recorded her impressions of him. (Book XIII, para X)
Let me describe the barbarian's appearance more particularly -he was so tall in stature that he overtopped the tallest by nearly one cubit, narrow in the waist and loins, with broad shoulders and a deep chest and powerful arms. And in the whole build of the body he was neither too slender nor overweighted with flesh, but perfectly proportioned and, one might say, built in conformity with the canon of Polycleitus. He had powerful hands and stood firmly on his feet, and his neck and back were well compacted. An accurate observer would notice that he stooped slightly, but this was not from any weakness of the vertebrae of his spine but he had probably had this posture slightly from birth. His skin all over his body was very white, and in his face the white was tempered with red. His hair was yellowish, but did not hang down to his waist like that of the other barbarians; for the man was not inordinately vain of his hair, but had it cut short to the ears. Whether his beard was reddish, or any other colour I cannot say, for the razor had passed over it very closely and left a surface smoother than chalk, most likely it too was reddish. His blue eyes indicated both a high spirit and dignity; and his nose and nostrils breathed in the air freely; his chest corresponded to his nostrils and by his nostrils . . . the breadth of his chest. For by his nostrils nature had given free passage for the high spirit which bubbled up from his heart. A certain charm hung about this man but was partly marred by a general air of the horrible. For in the whole of his body the entire man shewed implacable and savage both in his size and glance, methinks, and even his laughter sounded to others like snorting. He was so made in mind and body that both courage and passion reared their crests within him and both inclined to war. His wit was manifold and crafty and able to find a way of escape (lit. " handle ") in every emergency. In conversation he was well informed, and the answers he gave were quite irrefutable. This man who was of such a size and such a character was inferior to the Emperor alone in fortune and eloquence and in other gifts of nature.
Bohemond's initial intent was to secure some lands for himself around Constantinople, but instead he joined the First Crusades and was rewarded with a governorship of the Antioch province.For insight into the motivation and strategy of the first Norman Crusaders, the military crusade of Bohemond of Taranto is instructive.  In Book XIII  of the Alexiad, Anna Comnena also describes the difficulty of Bohemond created in attacking his Byzantine allies.
Now, as we have said, the tyrant Bohemond crossed with an enormous fleet from the other side into our country and then poured his whole Frankish army over our plains. From there he marched on Epidamnus in battle-order thinking he might perhaps be able to take it without a blow;

Introduction to the First Crusades 1096 - 1099

Most of the participants in the First Crusade were from the north of France, including Pope Urban II.  A great many other Europeans resisted joining this First Crusade, notably the Germans and most Italian seaport cities.  Only Genoa offered support for the campaign, which is itself odd, because its location on the West coast of Italy made preparations by sea that much more difficult.  The Venetians resisted because the Crusades threatened their monopoly trading position as middle merchants between Constantinople and the Levantine cities of the Middle East.Europe's motivation to invade the Middle East and occupy Syria, Palestine and the City of Jeruslaem requires an examination of the material and ideological causes of warfare.  War is an expensive option. In the late 11th century, the success of Seljuk Turkic expansion and rule along the Syrian coast, their domination over the key trade cities of Damascus, their pressure on Constantinople and Cairo, constrained European markets.  When the Seljuks took over Jerusalem in the late 11th century, they allowed Christian monasteries and churches to remain.  There is little evidence that the Seljuk Muslims persecuted or desecrated Christian institutions.  Therefore the choice of Pope Urban II in 1095 to proclaim a Crusade or Holy War to be sanctioned by the combined forces and financial support of the Church and the various royal states must be explained on grounds other than the rush to save Christian practice in Jerusalem or the Holy Land.

By 1098 The Crusaders had beseiged and taken Antioch, but it took another year to capture Jersualem. The crusaders divided their conquered lands into four separate states, including Antioch which was occupied and controlled by the Normans.

Jerusalem:  To understand the importance of Jerusalem as a center of three religious faiths, see this interactive tour of the Haram al-Sharif, the large plaza built on the old Jewish temple's foundation and encompassing the two important Muslim shrines and mosque complexes, the Dome of the Rock and the Mosque al-Aqsa.  There is also a 360 panorama tour you can take in Jerusalem Through Time.

The Normans in Europe: an Introduction

The power of the Norman kingdoms and empire from the late 11th to 12th century reflects a greater concentration of land ownership by the ari...