Byzantine Emperors and their relatives met many violent deaths. The favored ways of getting someone out of the way were poison, strangling, and blinding. The last one was the fate of Emperor Isaac who had married his sister to Conrad of Tyre. By 1195, he had presided over many military losses, from the early ravages of German Third Crusaders to defeats to the Turks in Bulgaria. The Emperor’s brother Alexios took over, with the army’s support, and Isaac himself was arrested and blinded. He spent eight years in prison, but he survived to have a short second act as Emperor.
Isaac’s son was also called Alexios. He was arrested with his father; however, he not only survived but escaped. Isaac’s daughter Irene had been married off to the King of Germany, who exerted himself to get his father-in-law and/or brother-in-law out of the dungeon. Some Italian merchants smuggled Alexios out of the dungeon and the city, bringing him to Swabia (southern Germany) in 1201. A year later, Prince Alexios met Boniface of Montferrat, a leader of the Fourth Crusade.
What Boniface told Alexios interested him very much. Here’s where things stood.
There had already been a Part A of a Fourth Crusade. Remember the German Emperor, Frederick Barbarossa, who had drowned in a river when his horse slipped on a rock at the start of the Third Crusade. His son, Henry VI, was the same German king who held Richard the Lion-Heart for ransom, releasing him in 1194 on the payment of 150,000 silver marks. Probably using some of that ransom money, in 1197 Henry VI set out with a German army to Syria, where he took back Beirut and Sidon. The German crusade ended suddenly when Henry VI died along the way; his men fled to Tyre and then made their way home.
Pope Innocent III was the youngest Pope in many years when he succeeded to the Throne of Peter in 1198. He was energetic and ambitious; he wanted to lead a Crusade himself. Although this didn’t work out, he was able to motivate a group of European noblemen to cobble together a Crusade plan at a tournament.
The English and French kings were at war, and the English were often at war among themselves, leading up to the barons’ forcing King John to sign the Magna Carta in 1215. Richard had drained them; they had no spare funds for an idealistic military venture. But the counts and knights who decided to put something together anyway turned out not to have enough money either. And that was the original problem, from which everything went sideways and downhill.
Earlier Crusades had gone overland through Hungary and Turkey; this was always very dangerous and now that the Crusaders only held a few port cities, it made much more sense to go by sea. A sea approach could also allow them to attack the port cities of Egypt, Saladin’s home territory, too.
The Counts of Blois, Burgundy, Champagne and Montferrat began by negotiating with the Doge of Venice for a fleet of ships. They settled on a price for transporting about 34,000 men and 4000 horses. In order to meet their obligations, Venice shut down most ordinary commercial shipping and building. For a year, they just built Crusade transport ships.
Some of the knights made their own arrangements and came through other ports, but the majority of the men assembled in Venice in May 1202. They planned a quick passage to Egypt, with the Pope’s blessing. Innocent III made them all vow to do precisely what they were supposed to do and nothing else, especially not attacking any Christian cities.
BUT….the Crusaders ran into a problem faced by many people who have planned festivals and conventions: they had way overbooked, considering the number of men who actually showed up. The Crusaders could not fill all of the ships Venice had built but the Doge expected to be paid for them all. They simply did not have enough money, and there was no refund policy.
Just like that, the Fourth Crusade was in debt. They paid Venice everything they had set aside for the actual war, but it was still not enough. The Doge threatened to hold their leaders under arrest until the total was paid. Then he had an idea.
The Doge suggested that they put the Crusade on hold, and just do a little mercenary work for Venice. Along the eastern side of the Adriatic Sea, there were many cities that used to pay tax to Venice but had broken away to Croatia or Hungary. The European army could restore Venice’s tax base by shaking down the Adriatic coast. Just force them to pay up.
The Crusaders pressured a few cities and then settled in to besiege the town of Zara. It was a Roman Catholic city and Hungary’s king was also Roman Catholic, so it was off limits for Crusading. The Pope was furious and excommunicated many of them. But they reasoned that they were simply acting as debt collectors to pay their passage; it was just a side job. Count Boniface of Montferrat decided to avoid the Zara siege and make a short jaunt north to see his cousin, the King of Germany. There he met Prince Alexios, who was looking for an army.
Boniface had a big idea: the Fourth Crusade could back off on the Adriatic towns and instead, re-install Prince Alexios in Constantinople. Alexios had little cash, but he was happy to promise them very large payments when he could get the money from the treasury. True, Constantinople was a Christian city, but it wasn’t a Roman-ruled one. They could justify conquest as a way to reunite the Eastern and Western churches under Rome. Wouldn’t that be worthy? So spiritual.
The other Crusade leaders were taken aback; their men had vowed to go to Jerusalem. But the Doge of Venice loved the plan and was happy to use his fleet to transport them. The Doge’s pressure convinced most of them to sign on, although at this point, some went home.