siege engines of the Crusaders
It was the year of 1099 and the Crusaders were besieging Jerusalem. The warriors taking part in this First Crusade had left their homes at the beginning of 1096 and had been on the move for three years. They had sailed the Mediterranean and landed on the beaches of Bosphorus where a long and difficult march awaited them. There were mountains, desert plains, and rivers to be crossed and they were always haunted by the fear of ambush by their enemies, the Turks. Up till now the Crusaders had won all their battles and conquered several cities, such as Nicaea, Edhessa, Antioch, and Tripolis in Syria. Only a quarter of the force which had set out from Europe now remained. They had reached their ultimate objective, Jerusalem. But the conquest of the city proved far from easy. The Crusaders besieged the town for several months and had to make use of every known war machine and device. In a siege three types of machine were used: those for throwing missiles, those for battering – to open a breach in a wall – and those which protected the men approaching the walls.
The mangonel and the trebuchet were the principal throwing weapons. They were made of a strong beam which turned on an axle held by two trestles. The longer arm of the beam ended in a sort of spoon which could hold the missile and at the end of the shorter arm was a heavy counterweight so that, when not in use, the longer arm stood up. To use the machine the longer arm was pulled down with ropes and the missile was put into the 'spoon'; the counterweight was now raised high so that when the crew let go of the ropes, the longer arm would swing up rapidly.
A strong bar brought the rotation to a sudden stop and the missile would be violently jerked forward. Modern calculations show that a trebuchet with a throwing arm (18 foot long) and a short arm (6 foot long) bearing a counterweight of 3 tons can throw a missile of 2 hundredweight to a distance of 80 yards. It is believed, however, that the Crusaders had built even more powerful trebuchets.
Apparently the crusaders learned to make these war machines – based on the principle of the lever – from their enemies, the Arabs themselves. In weapons of this type the sinews of animals or twisted ropes had previously been used as a means of propulsion.
Mangonels and trebuchets did not only throw stones. There were other missiles called 'bombs'. These consisted of wood or earthenware receptacles full of a combustible substance called 'Greek fire'.
'Greek fire' was a mixture of naphtha, pitch, and resin and sulphur; it was ignited immediately before throwing and the shell, on reaching its objective, would burst and scatter fiery load.
Since all war machines were made of wood, the incendiary 'bombs' could cause very severe damage.
The ballista and machines of the same type threw heavy darts and quarrels (square-headed arrows), red-hot iron bars, and darts tipped in 'Greek fire'. They all consisted of a huge bow, mounted on a support with wheels. Arms of this type were very popular in the Middle Ages since they could be moved easily from place to place and permitted accurate aiming.
The battering rams used by the Crusaders to breach the walls of a besieged town, were the same as those once used by the Romans. To protect the crew operating the ram, the machine was enclosed in a cage covered with hides which were drenched in water as a precaution against burning missiles.
Mantelets were wooden shields, mounted on wheels, behind which several warriors could find shelter from enemy arrows and missiles as they advanced towards the besieged city. (The same word is used today for a bullet-proof screen for gunners.)
Assault sheds – These sheds shielded the advance of warriors. They were long and moved on rollers and afforded protection from the arrows, stones, pitch and boiling oil which the besieged rained down on them. They could shield a larger number of men than a mantelet. Thus protected the Crusaders could reach the moat of the town and pour earth into it, filling it up so that assault towers and ladders could be brought right up against the wall. If a surprise attack was planned, they could not, obviously, use towers and had to rely on ladders only.
Ladders – First of all the mangonels concentrated their fire on a section of the wall, while bowmen shot volleys of arrows from the towers, until the defenders were obliged to leave that section. This was the moment when the besiegers swarmed up ladders and established a foothold on the wall. There were ladders of many types: in sections, flexible, and armed with hooks that could grip the stonework.
But the war machines which brought victory to the Crusaders at the siege of Jerusalem were the siege towers.
Siege towers – Many of these machines had been brought all the way from Genoa. They had been built there and then dismantled; the sections were carried n the ships of the Ligurian fleet to the ports of Syria, then dragged by the armies as far as the walls of Jerusalem where they were reassembled by skilled carpenters.
It was one of these huge machines that, strategically manoeuvred, made the first breach in the Moslem defensive lines. The assaulters on the top of the tower were able to shoot volleys of arrows against the defenders from a higher level and at the right moment were able to jump down onto the battlements.