God's War: A New History of the Crusades

promoted glamour and outrageous ambition he was to become, seemed, in his inheritance of Sicily, Germany and the imperial dignity, to represent a new secular order in Christendom, for the moment allied with the papacy. His arrival was regarded as totemic of optimism and success. As Peter of Montague, Master of the Temple, put it, the emperor was ‘long expected’.⁶² As late as 1221, one compelling argument against accepting apparently generous peace terms was that Frederick had forbidden any deal prior to his own arrival.⁶³ No secular figure could replace him, not even his representatives in 1220–21. Frederick’s absence unsettled tactical considerations and strategic planning. Cardinal Pelagius, representing the other universal power, had the unenviable task of trying to maintain the crusade until the emperor was ready to join it.

This was made considerably more difficult by the rhythm of departures and arrivals. The regularity of the two annual passages, the number of ships and crusaders carried provided remarkable testimony to the development of Mediterranean shipping and trade routes during the twelfth century. It did little to support an effective military campaign. A key element in previous long crusading expeditions had been the emergence of an esprit de corps based on shared expedience rather than shared origins – 1097–9, 1191–2, 1203–4. During the operations around Damietta from May 1218 to September 1221, death or departure deprived the Christian army of consistent command. Not a single great western lord remained in the Nile Delta for the complete duration of the war. Oliver of Paderborn was one of a very few leading clergy who did. In contrast with the Third Crusade, the Outremer barons, clergy and the masters of the military orders, spent significant passages of time away from the front line. Pelagius’s continuous presence from the autumn of 1218 of itself added to his influence. Each newly arrived contingent was balanced by the departure of others.⁶⁴ Few seemed reconciled to staying until the Egyptian campaign was completed or Jerusalem recovered. As with the Albigensian wars, crucesignati appeared to believe that seeing only limited active service in the cause of the cross was sufficient to merit the indulgence. Although Quia Maior and Ad Liberandam indicated that Innocent III envisaged a campaign lasting three years or more, in neither was any conditional time limit set for the enjoyment of the plenary indulgence. The temporary quality of the crusaders’ commitment exerted a powerful influence. Even the legate’s threats of excommunication failed to prevent some, such as the count of Katzenellenbogen in 1220, from deserting.⁶⁵ In October 1218, the news of crusaders leaving encouraged the Muslims to attack the Christian camp. Later, the pressure to retain as many troops as possible on station prompted Pelagius in 1220–21 to argue for a more aggressive policy. Without fighting and the prospect of booty or success, hanging about in Damietta indefinitely was hardly an attractive or sustainable option. Equally damaging, the incessant merry-go-round of arrivals and departures consolidated the regional, national and social divisions that dominated the public and private debates on the course the campaign should take, a disunity fed by the lack of an accepted single leader.

Technology assumed a central place in the Egyptian campaign. Eyewitnesses noted when new crusaders brought with them siege equipment, as they had during the siege of Acre during the Third Crusade. Apart from the contest of throwing machines on both sides, much of the fighting was determined by the respective merits of the attackers’ and defenders’ engineering and shipping as the struggle was played out across the Nile around Damietta and later, in the summer of 1221, upstream towards Cairo. Water protected and threatened by turns in a landscape where military aggression was fraught with hazard as it almost invariably required crossing rivers or canals. The first great obstacle, the seventy-foot-high Chain Tower, situated in the Nile between Damietta and the crusader camp, was separated from the Christian-held left bank by a narrow channel. From the tower to the city walls ran a chain, restored by Saladin, that was raised to prevent unwelcome river traffic proceeding up the Nile. It was only captured in August 1218 thanks to an elaborate floating fortress designed by Oliver of Paderborn himself.⁶⁶ Although paid for and built by the Germans and Frisians, the design – a fortified platform equipped with scaling ladders suspended above two large ships lashed together – resembled the devices constructed by the Venetians before the walls of Constantinople in 1204. A number of Venetian maritime experts may have been on hand, left behind to find new clients when Andrew of Hungary decided to return home overland.

Oliver’s engine was needed because the garrison of 300 in the Chain Tower could not be starved out as a bridge of boats supplied the tower from Damietta. Another pontoon bridge further upstream protected the Ayyubid camp at al-Adilyah, south of the city, as well as allowing Muslims to attack crusader positions across the river. This bridge became the focus of operations for both sides, producing one of more remarkable engineering feats of the campaign. To outflank the bridge, the crusaders dredged and enlarged the al-Azraq canal, which ran for some miles, linking the Mediterranean coast to the Nile south of the Christian camp and upstream of Muslim defences, which now included hulks scuttled in the main channel of the river.⁶⁷ The enlargement of the canal took a month. Any immediate advantage was dissipated by a devastating storm and flood of seawater in late November that almost engulfed the two hostile camps, followed by an epidemic, possibly of scurvy. Christian fatalities may have been as high as 20 per cent.⁶⁸ However, after a grim and unsettled winter, the engineering efforts of the previous autumn contributed to the occupation of the Ayyubid camp on the right bank of the Nile in February 1219 which had been deserted as a consequence of an attempted coup against the new sultan al- Kamil.⁶⁹

Thereafter, the lack of adequate technological capacity first blunted the crusaders’ attempts to take the city during the summer of 1219 and later, on the march south in July and August 1221, placed the western host at a fatal disadvantage. The lack of manpower, exacerbated by the departure in the spring of 1219 of Leopold of Austria and many others the following autumn, proved significant. This left the crusaders outnumbered and unable to press forward attacks. Muscle power, human or animal, provided the energy upon which the army depended, a role taken in much later centuries by gunpowder, petrol and electricity. Among the skills well represented on all crusading expeditions, those of the carpenter stand out. John of Brienne employed one of his, Aubert the Carpenter, to reconnoitre the deserted Ayyubid camp in February 1219.⁷⁰ On land or water, wood technology occupied a central place in medieval warfare. The Nile Delta presented peculiar problems, not least its lack of suitable local timber, a point recognized by Innocent III’s attempt to ban western exports of wood or ships to Egypt in 1213 and 1215. From the winter of 1218–19, although able to maintain a blockade of Damietta once the city was encircled in February, the crusaders made no progress and were only barely able to resist counter-attacks by Sultan al-Kamil, now stationed further to the south. In the event, the blockade worked, starving the city so that resistance slackened, an unguarded section of wall leading to its fall in November 1219. The main bulk of the Muslim forces were deliberately never engaged. When, finally, almost two years later, they were, the crusaders’ technological limitations were exposed. They lacked sufficient flat-bottomed barges to carry the bulk of the army and so had to maintain a precarious link between the land army and many of its leaders, including the legate, on board ship. This form of amphibious warfare was beyond the experience of many, the departure of Frisians and Netherlanders over the previous two years being keenly felt. The absence of adequate craft in sufficient numbers allowed the Egyptians to outmanoeuvre the crusaders. By using shallow side canals, the Muslims cut them off from their base at Damietta and imperilled any chance of retreat once the Christians pressed southwards into the heart of the Delta beyond Sharamsah in late July 1221.⁷¹

Yet these problems of leadership, manpower and technology did not prevent the crusade from threatening the survival of the Ayyubid empire, if only, but especially, in the minds of Egypt’s defenders. From their discomfort came a policy of military containment and appeasing diplomacy, which unlike the Richard–Saladin negotiations over Palestine in 1191–12, nonetheless failed seriously to engage the Christians. On this failure, traditionally blamed on the myopic stubbornness of Cardinal Pelagius, the crusade has been seen by many to have foundered. In fact, the objectives of each side were incompatible. The fragile unity of the Ayyubid empire was severely shaken by the death of Sultan al-Adil in August 1218, just after the fall of the Chain Tower.⁷² Thereafter, no claimant to the succession among his sons or nephews could realistically have surrendered control of Palestine, still less the Holy City of Jerusalem, any such offers being so territorially circumscribed as to be unconvincing. The Ayyubid military weakness exposed by the simultaneous attack on Egypt by the crusaders and on Aleppo by the Seljuks in 1218 imposed a temporary unity of self-interest on the rival dynasts. Hard-pressed al-Kamil, al-Adil’s son and successor in Egypt, received vital help from his brother al Mu ‘azzam of Damascus. Al Mu ‘azzam campaigned in Egypt in 1219 and 1221 and launched a series of assaults on Frankish positions in Syria, recapturing Caesarea late in 1219 and in 1220 threatening Acre and Chateau Pelerin. Yet it was entirely unclear whether al-Kamil exerted sufficient control over Palestine for any promise to restore Jerusalem to the Christians to be implemented. The Franks may have known this. The hollowness of any negotiated return of Jerusalem was emphasized when al Mu ‘azzam dismantled its walls in 1219 and ordered further demolition in the city in 1220.⁷³