The process would assuredly be a long one, for men who fought so stoutly would resist starvation with equal tenacity; besides, the duration of the siege was already beginning to excite discontent among the allies, whose wars were generally of very short duration.

The Spaniards, too, were suffering from severe illness brought on by fatigue, exposure, and hardship.
It was now determined to make a grand effort to obtain possession of the great market of Tlatelolco, which lay on the northwestern part of the city.

Its possession would enable the force of Cortez to join hands with those of Alvarado and Sandoval; and the spacious market itself, with its halls and porticoes, would furnish accommodation for the army; and enable them to attack the city at close quarters, instead of having to fight their way, every day, along the causeway.
Sandoval was to join Alvarado, sending seventy picked troops to support Cortez.

Advancing along the causeway, and supported not only by the ships, but by a countless host of canoes filled with the allies of the lake cities, who penetrated the canals, and caused confusion in the rear of the Aztecs, the division of Cortez cleared the suburbs of their opponents, and then advanced towards the square of Tlatelolco by three great streets.
Alderete commanded the force that advanced by the main central avenue.

This was a raised causeway, with canals running on either side of the road.