The rewards that Alexius IV had promised to the forces of the Fourth Crusade for assaulting Constantinople in July 1203 and placing him on the throne of the Byzantine Empire in his uncle's stead proved chimerical. Alexius's efforts to raise the funds through new taxes eroded his own support in the city. His promise to place the Byzantine Church under the authority of the Pope at Rome provoked still more anger and opposition. At the same time the Crusader forces, encamped across the Golden Horn at Galata, proved to be disruptive guests on their occasional forays into the city. With the onset of winter, events unravelled the expectations of all of the parties--with the possible exception of Doge Enrico Dandolo, who had longer vision and greater ambitions for Venice.

The drama's final act began in January 1204. The Byzantine nobleman Alexius Ducas treacherously organized the assassination of the Angelus family's co-Emperors Isaac II and Alexius IV, arranged his own coronation as Alexius V, and moved swiftly to strengthen the city's fortifications against the renewed Crusader attack that was certain to follow by Spring. For the Crusaders, however, the first order of business was to decide how to divide the spoils that they confidently anticipated from their conquering and pillaging of the great capital city. Since they also intended to appropriate the throne of the Byzantine Empire for one of their own number, a secondary issue was to settle upon a method for selecting the new ruler.

The selection of the new ruler was placed in the hands of a 12-man electoral committee. Six of the members were to be appointed by Doge Dandolo and the Venetians, the balance by the other Crusaders. The new Emperor, whoever he might be (and he was expected to be one of the French noblemen among the Crusaders), would receive one-fourth of Constantinople and the Byzantine Empire; the rest of the city and empire would be allocated one-half to Venice and one-half to the other Crusaders.

With the serious business thus resolved, the war could begin. The assault, begun in April, was more difficult than the one of the prior year, but the Crusaders prevailed. Horrific looting of the world's richest city continued for days. Among the art treasures seized by the Venetians were the four graceful horses that now stand above the portal of the Basilica of St. Mark at Venice and the vast quantity of jewels and semi-precious stones that adorn the Basilica's pala d'oro. In geopolitical terms, however, Venice's greatest rewards were possession of the eastern shore of the Adriatic, the Cyclade and Sporade islands, and the shores of Thessaly, the Sea of Marmara and Black Sea, cementing its control of the trade routes from Europe to both Constantinople and Asia Minor. To these Venice quickly added--by treaty and by force of arms--the island of Crete, commanding the approach to the Adriatic Sea.