The military history of the Crusader states begins with the formation of the County of Edessa in 1097 and ends with the loss of Ruad in 1302, the last Christian stronghold in the Holy Land.
The Seljuk–Crusader war began when the First Crusade wrested territory from the Seljuk Turks during the Siege of Nicaea in 1097 and lasted until 1128 when Zengi became atabeg of Aleppo.
That year in the Battle of Artah, the Principality of Antioch under Tancred won a victory over Fakhr al-Mulk Radwan of Aleppo and put the city on the defensive.
When the Crusaders failed to put an army into the field to oppose him, he captured the Syrian towns of Atharib, Zerdana, Ma'arrat al-Numan and Kafr Tab.
The crowning achievement of Imad-ud-din Zengi's career occurred when he moved against the Christian state of Edessa when the bulk of its forces were campaigning elsewhere.
The Egyptians were nevertheless able to hold onto the key fortress, which served as a launching point for raids on the newly established Kingdom of Jerusalem until 1153 when it fell in the Siege of Ascalon.
From 1163 to 1169, Egypt became the prize of a struggle between King Amalric of Jerusalem and Nur ed-Din of Syria as the Fatimid factions invited one side or the other to intervene in their civil war.
With a bit of hyperbole, the contemporary Byzantine scholar Anna Comnena noted that a Frank on horseback would "make a hole through the walls of Babylon.
Whereas the Crusaders developed a healthy respect for the harass-and-surround tactics of the Turkish horse archers, they tended to discount the effectiveness of the Egyptian armies.
A prior expedition, the People's Crusade, made up of peasants and low-ranking knights arrived in Asia Minor in August 1096, but were decisively defeated by Seljuk forces a month later in October.
The long distance to the Middle East and the difficulty in crossing often hostile territory resulted in the Crusader forces being relatively outnumbered by the surrounding pre-existing nations.
Although often no clear result appeared in running battles, there could be a chance for the Crusaders to charge into unprepared and disorganised enemy forces after some time had passed.
The more well-off Crusader troops, such as the knights, were individually superior in a melee to any cavalry in the area at the time, and were relatively immune to arrows due to their armour.
The Seljuks attempted to use this on several occasions to draw small groups of cavalry away from the main body where they could be destroyed piecemeal by superior numbers.
An alternative or supporting tactic to feigned retreats that was used by the Seljuks and others was harassing the Crusader line to disorganise it and leave it open to a cohesive cavalry charge.
Crusader generals would have needed to be careful to maintain discipline in the face of losses from arrows and to keep heavy cavalry reserves to repel probing attacks.
Note that this analysis is only drawn from examination mainly of some battles between 1097 and the mid 12th century, and so does not include the tactics of the entire Crusader period which only truly ended in 1302.
They would also take part in many defences in the crusader kingdom such as Antioch and finally Acre committing to many sallies in last-ditch efforts to deny the cities to the enemy.
Also, they held some of the strongest castles in the kingdom, for example Krak des Chevaliers, which was primarily controlled by the Knights of Saint John.
The only effective defensive method of defeating the hit and run tactics launched by the Saracens was to form a shield wall and hope that the armour one wore was thick enough.
Many have argued that the cause of victory was due to factional infighting between the various Turkish tribes within the army, as opposed to the Christian zeal inspired by the Lance of Longinus that was supposedly found in the city.
Building many fortifications, which were well-supplied with water and food, they could hold out almost indefinitely, unless supply was cut, the enemy infiltrated the fort such as Krak des Chevaliers or a big enough force was marshaled against them in a siege such as by Saladin, who only captured Jerusalem after destroying the Crusader army at Hattin.
Pitched battles were avoided as often as possible, unless the political situation called for it, due to problems with manpower, logistics and the impracticability of marching armoured soldiers in such a hot climate.
Since troops were being brought over from such a long distance, Crusader leaders feared that one would plot against the other back in Europe, something that their Saracen counterparts had little worry of considering that their lands were already occupied.
As a result, the Saracens had a seemingly unlimited supply of men, whilst the crusaders struggled to man their walls during the latter periods in the late thirteenth centuries.
Over time, The Templars grew to an impressive order of thousands of members, though not all would have been heavy cavalry – most would have been squires or servants accompanying the Knights.
Their mission, like many of the other military orders, was to protect pilgrims heading from Northern Spain, which in the twelfth century was Christian, into the Islamic south and then to the Holy land.
However, the descendants of these Knights formed the elite Prussian officers and such the legacy of the order's martial skill can be examined in the Napoleonic and the Franco-Prussian War.
This daunting task across the desert is made all the more uncomfortable when considering the weight arms, armour, and baggage, combined with the threat of getting lost while surrounded by the enemy.
However, siege equipment was used, although a favourite tactic of all Medieval European armies was a simple blockade and then wait for a few months or so for the defenders to run out of water, food, or both.