On the Conquest of Constantinople is one of the most important historical sources on the Fourth Crusade and the Sack of Constantinople.

While the first three Crusades were launched in an effort to reclaim Jerusalem from Muslims, the Fourth Crusade, begun in 1202, pitted Christians against Christians: Roman Catholics against Orthodox.

Planned as a holy war to retake Jerusalem, the Fourth Crusade ended in disaster when crusaders sacked Christian Constantinople. Why did this crusade go so wrong? What Ronald Reagan said about tariffs ...