The mess over Capistrano and the general unsavoriness of this batch of tourists combined to push me into abysses of gloom.

I moved grimly along from epoch to epoch, but my heart wasn’t in it. And by the time, midway through the second week, that we reached 1204, I knew I was going to do something disastrous.

Doggedly I delivered the usual orientation lecture.

“The old spirit of the Crusaders is reviving,” I said, scowling at Bilbo, who was fondling Miss Pistil again, and scowling at Sauerabend, who was visibly dreaming of Palmyra Gostaman’s meager breasts. “Jerusalem, which the Crusaders conquered a century ago, has been recaptured by the Saracens, but various Crusader dynasties still control most of the Mediterranean coast of the Holy Land. The Arabs now are feuding among themselves, and since 1199, Pope Innocent III has been calling for a new Crusade.”

I explained how various barons answered the Pope’s call.

I told how the Crusaders were unwilling to make the traditional land journey across all of Europe and down through Asia Minor into Syria. I told how they preferred to go by sea, landing at one of the Palestinian ports.

I discussed how in 1202 they applied to Venice, Europe’s leading naval power of the time, for transportation.

I described the terms by which the ancient and crafty Doge Enrico Dandolo of Venice agreed to provide ships.

“Dandolo,” I said, “contracted to transport 4,500 knights with their horses, 9,000 squires, and 20,000 infantrymen, along with nine months’ provisions. He offered to throw in fifty armed galleys to escort the convoy. For these services he asked 85,000 silver marks, or about $20,000,000 in our money. Plus half of all the territory or treasure that the Crusaders won in battle.”

I told how the Crusaders agreed to this stiff price, planning to cheat the blind old Doge.

I told how the blind old Doge, once he had the Crusaders hung up in Venice, gripped them by the throats until they paid him every mark due him.

I told how the venerable monster seized control of the Crusade and set off in command of the fleet on Easter Monday, 1203 — heading not for the Holy Land but for Constantinople.

“Byzantium,” I said, “is Venice’s great maritime rival. Dandolo doesn’t care warm spit for Jerusalem, but wants very badly to get control of Constantinople.”

I explicated the dynastic situation. The Comnenus dynasty had come to a bad end. When Manuel II died in 1180, his successor was his young son Alexius II, who shortly was murdered by his father’s amoral cousin, Andronicus. The elegantly depraved Andronicus was himself destroyed in a particularly ghastly way by an enraged mob, after he had ruled harshly for a few years, and in 1185 there came to the throne Isaac Angelus, an elderly and bumbling grandson of Alexius I, by the female line. Isaac ruled for ten haphazard years, until he was dethroned, blinded, and imprisoned by his brother, who became Emperor Alexius III.

“Alexius III still rules,” I said, “and Isaac Angelus is still in prison. But Isaac’s son, also Alexius, has escaped and is in Venice. He has promised Dandolo huge sums of money if Dandolo will restore his father to the throne. And so Dandolo is coming to Constantinople to overthrow Alexius III and make Isaac into an imperial puppet.”

They didn’t follow the intricacy of it. I didn’t care. They’d figure it out as they saw things taking place.

I showed them the Fourth Crusade arriving at Constantinople at the end of June, 1203. I let them see Dandolo directing the capture of Scutari, Constantinople’s suburb on the Asian side of the Bosphorus. I pointed out how the entrance to the port of Constantinople was guarded by a great tower and twenty Byzantine galleys, and blocked by a huge iron chain. I called their attention to the scene in which Venetian sailors boarded and took the Byzantine galleys while one of Dandolo’s ships, equipped with monstrous steel shears, cut through the chain and opened the Golden Horn to the invaders. I allowed them to watch the superhuman Dandolo, ninety years old, lead the attackers over the ramparts of Constantinople. “Never before,” I said, “have invaders broken into this city.”

From a distance, part of a cheering mob, we watched Dandolo bring Isaac Angelus forth from his dungeon and name him Emperor of Byzantium, with his son crowned as co-emperor, by the style of Alexius IV.

“Alexius IV,” I said, “now invites the Crusaders to spend the winter in Constantinople at his expense, preparing for their attack on the Holy Land. It is a rash offer. It dooms him.”

We shunted down the line to the spring of 1204.

“Alexius IV,” I said, “has discovered that housing thousands of Crusaders is bankrupting Byzantium. He tells Dandolo that he is out of money and will no longer underwrite their expenses. A furious dispute begins. While it proceeds, a fire starts in the city. No one knows who caused it, but Alexius suspects the Venetians. He sets seven decrepit ships on fire and lets them drift into the Venetian fleet. Look.”

We saw the fire. We saw the Venetians using boat-hooks to drag the blazing hulks away from their own ships. We saw sudden revolution break out in Constantinople, the Byzantines denouncing Alexius IV as the tool of Venice, and putting him to death. “Old Isaac Angelus dies a few days later,” I said. “The Byzantines find the son-in-law of the expelled Emperor Alexius III, and put him on the throne as Alexius V. This son-in-law is a member of the famous Ducas family. Dandolo has lost both his puppet emperors, and he is furious. The Venetians and the Crusaders decide now to conquer Constantinople and rule it themselves.”

Once again I took a pack of tourists through scenes of battle as, on April 8, the struggle began. Fire, slaughter, rape, Alexius V in flight, the invaders plundering the city. April 13, in Haghia Sophia: Crusaders demolish the choir stalls with their twelve columns of silver, and pull apart the altar, and seize forty chalices and scores of silver candelabra. They take the Gospel, and the Crosses, and the altar cloth, and forty incense burners of pure gold. Boniface of Montferrat, the leader of the Crusade, seizes the imperial palace. Dandolo takes the four great bronze horses that the Emperor Constantine had brought from Egypt 900 years before; he will carry them to Venice and place them over the entrance to St. Mark’s Cathedral, where they still are. The priests of the Crusaders scurry after relics: two chunks of the True Cross, the head of the Holy Lance, the nails that had held Christ on the Cross, and many similar objects, long revered by the Byzantines.

From the scenes of plunder we jumped to mid-May.

“A new Emperor of Byzantium is to be elected,” I said. “He will not be a Byzantine. He will be a westerner, a Frank, a Latin. The conquerors choose Count Baldwin of Flanders. We can see his coronation procession.”

We waited outside Haghia Sophia. Within, Baldwin of Flanders is donning a mantle covered with jewels and embroidered with eagle figures; he is handed a scepter and a golden orb; he kneels before the altar and is anointed; he is crowned; he mounts the throne.

“Here he comes,” I said.

On a white horse, clad in glittering clothes that blaze as if on fire, Emperor Baldwin of Byzantium rides forth from the cathedral to the palace. Unwillingly, sullenly, the people of Byzantium pay homage to their alien master.

“Most of the Byzantine nobility has fled,” I told my tourists, who were yearning for more battles, more fires. “The aristocracy has scattered to Asia Minor, to Albania, to Bulgaria, to Greece. For fifty-seven years the Latins will rule here, though Emperor Baldwin’s reign will be brief. In ten months he will lead an army against Byzantine rebels and will be captured by them, never to return.”