These mainly included cannons, pistols, horses, dogs, boats, and armor. .
The cannons scared the Aztecs by their size and sound, as well as the destruction they produced. The Broken Spears relates, "He [Motecuhzoma] was also terrified to learn how the cannon roared caused one to faint and grow deaf it comes out shooting sparks and raining fire smells like rotten mud the odor penetrates the brain and causes great discomfort. If the cannon is aimed against a mountain, the mountain splits and cracks open - (Leon-Portilla, 30). The armor of the Spaniards was iron, which was not yet seen by the Aztecs (Leon-Portilla, 30), and provided better protection than the cotton used for protection by the Aztecs. There horses and dogs were also new to the Aztecs, as they were described as large deer (horses) and huge dogs with yellow eyes that "sparked- (Leon-Portilla, 30-31). .
Of utmost importance to the Spaniards success and edge on the Aztecans were there boats, or vessels. Not only were they their means of arrival to Mexico and the port of Vera Cruz in the first place, but they were the means in which Cortés and his men were able to return to the city of Tenochtitlan for the final besiege. As Meyer, Sherman, and Deeds note when discussing the final assault of the Spaniards on Tenochtitlan, "The small Spanish fleet was crucial to their strategy, for if the causeways could be commanded, all transportation and communication to the island could be cut off- (119). They were also a sizable defense against the Aztecs form of marine defense, their canoes.
Another main asset to the Spaniards' success was their leader, Cortés himself. Fernando Cortés was persistent, intelligent, and manipulative. Any sort of gain for the Aztecs didn't discourage Cortés, but rather encouraged him to find another way of advancement. .
Cortés' intelligence, both innate and acquired, helped his cause tremendously.
