Upon his return to Tenochtitlan in November 1520, Hernán Cortés found the city in open revolt against the Spanish conquerors. The conflict, known as the La Noche Triste (the Night of Sorrows), resulted in heavy losses for the Spanish and their indigenous allies. Cortés and his men were forced to retreat from the city, suffering significant casualties during the escape. The event marked a turning point in the conquest of Mexico, as it temporarily halted Spanish progress and allowed the Aztecs to regroup and strengthen their defenses.