Complex sentence: The French failed to raise sufficient funds for payment of the Venetians and diverted the crusade to the Christian city of Zara at the will of the Venetians to subsidize the debt.
Split into simpler sentences: The French failed to raise sufficient funds for payment of the Venetians. As a result, they diverted the crusade to the Christian city of Zara at the will of the Venetians to subsidize the debt.