The young Alexius, Isaac Angelus’s son, escaped from Constantinople to Sicily and made his way from there to the Swabian court. This was natural enough since his sister was the beloved wife of Swabia’s ruler. Alexius, in fact, had got away from Constantinople during the summer, and it is just possible that Philip of Swabia knew that his arrival was imminent when he invited Boniface to visit him.

If Philip needed a plausible excuse for the proposed diversion of the Fourth Crusade, and if Boniface was equally ready to use his position as its leader to misdirect it, both of them now had their wants supplied. It is still doubtful whether an attack on Constantinople can, at this moment, have been any more than a desirable but somewhat speculative scheme. Boniface and Philip knew that most of the knights and men-at-arms who would embark on the Crusade would never consider any idea of turning aside to attack Christian territory. They had an instrument in Alexius—no more—and they now needed a really valid reason to use him.

In February 1201, prior to the death of Tibald of Champagne and the appointment of Boniface to succeed him, six ambassadors had arrived in Venice from France empowered to treat with the Doge on the subject of transport for the Crusade. Venice had not been their first port of call, for they had previously been to both Genoa and Pisa, only to be told that the Genoese were unwilling, and the Pisans unable, to provide them with transport. It was for this reason, as Robert de Clari tells us, that they finally made the journey to Venice (they had probably hoped for better terms from the Genoese and Pisans). The ambassadors put their proposition to the Doge and his council who, after a week of discussion, agreed to transport the Crusaders at a price of five marks per horse, and two marks per man. According to Villehardouin who, as one of the leaders, was in a good position to know the figures, the Crusaders numbered 4,000 knights, each with his horses, 9,000 squires and 20,000 foot soldiers.[2] For the sum of 86,000 marks the Venetians agreed to carry the men and horses “to recapture Jerusalem,” and to victual them for a year. In addition, the Venetians said that they would “for the love of God” provide fifty armed galleys as escort, on condition that they should have half of any conquests that might be made. If the Crusade was to proceed, the ambassadors could do nothing but accept these terms. Nowhere else in Europe could they hope to find a maritime power capable of supplying them with the fleet that they needed.

Pope Innocent III was now acquainted with the terms of the contract. It was one to which he very reluctantly acceded. He had little reason to trust the Venetians, for he knew that they would transport anyone—Christian or Moslem—for a fee. As if well aware of the possibilities latent behind the present agreement, he inserted a clause to the effect that no Christian state must on any account be attacked and that, to ensure this, a papal legate must sail with the fleet. It is likely that he suspected Doge Dandolo of some design against Zara, but unlikely that he ever anticipated an attack on Constantinople. Subject to these conditions, then, it was understood by the Pope and by the Crusaders that the Venetian fleet would be transporting the army to Alexandria in Egypt.

There were very good reasons for attacking Egypt. Once the port of Alexandria had been taken, it would be comparatively easy to keep the army supplied and reinforced by the sea-route from Europe. The old Crusader route across the Dardanelles and down through Asia Minor to Syria had become increasingly dangerous owing to the mounting power of the Turks, who were in the process of absorbing all of Anatolia. In the Third Crusade, the magnificent German army under Frederick I, Emperor of the West, had been bled to death in battle after battle against the Turks. When it finally won through to Acre no more than 1,000 men remained.

Egypt at this moment was weakened by a recent civil war. The Nile had failed to inundate the land for five whole years, with the result that the Egyptians were starving, and their morale had collapsed. Egypt, nevertheless, was the mainstay of Arabic wealth and if it could be captured, a wedge would be driven between the Moslem world to the east and the western territories of North Africa. There was every good reason, then, why the Crusaders should decide on Egypt as the target for their expedition. Once they had established their base and headquarters in Egypt, they could keep a steady transfusion of men and matériel flowing in from their native countries. At the same time they themselves could live off the land of Egypt—for the Nile would not consistently fail and even if the Egyptians starved there would always be plenty of grain and other supplies sufficient for a relatively small Crusading army.

One thing the Crusaders did not know was that, while they were conducting negotiations with the Venetians for their transport, the Venetians were in Cairo, possibly concluding what amounted to a non-aggression pact with the Egyptians.[3]

In the spring of 1202, just over a year before the Crusade reached Byzantine territory and prepared to attack Constantinople, the Venetians were negotiating a trade agreement with al-Adil, Sultan of Egypt. The advantage of this agreement to Venice was immense, and it was largely upon it that so much of the city’s later fortune was founded. In return for a guarantee by the Venetians that they would prevent any Crusading army from attacking Egypt, the Sultan guaranteed them considerable trading concessions in Alexandria.

Egypt, with its outlet to the Red Sea and to the merchandise of India and the East, was in a position to control the flow to Europe not only of oriental luxuries but also of those spices upon which the preservation and enhancement of European food so largely depended during the winter months. It was unlikely, if they had concluded a trading agreement of such importance with the Sultan of Egypt, that the Venetians would willingly have countenanced any attack upon the Sultan’s domains.