Which Venetian doge convinced the Fourth Crusade to attack Constantinople?

Enrico Dandolo, the doge of Venice, helped persuade the Fourth Crusade to turn against Constantinople. The crusade had originally been organized to recover Jerusalem, with Egypt intended as the strategic target, but financial and political complications redirected it.

Venice had built a large fleet to transport the crusaders. When fewer soldiers arrived than expected, the crusaders could not pay the agreed cost. Dandolo proposed that they first attack Zara, a rebellious city under Hungarian protection. After Zara was captured in 1202, Byzantine dynastic politics offered another diversion.

Alexios IV Angelos promised money, troops, and church concessions if the crusaders helped restore his father, Isaac II, to the Byzantine throne. Dandolo supported the plan, and the army sailed to Constantinople. After Alexios failed to meet his promises and was overthrown, the crusaders attacked and sacked the city in April 1204.

Dandolo was a major strategist and advocate, but the diversion resulted from several leaders, debts, Byzantine rivalries, and shifting negotiations. Calling him the sole architect oversimplifies the episode, yet he is the canonical answer to this quiz question.