The Incas were one of the most complex 15th and 16th century empires of all time. One characteristic that the Inca were known for was their extremely large army and their intense warfare tactics. The Inca army was one of the largest armies of the 15th and 16th centuries. Although they were very numerous, they were also skilled fighters. The Inca army had the weapons and tactics to eliminate any enemy they wanted. In the Inca army they had a large amount of men. This is because in Inca times every man had to serve in the military due to the socialist structure of these civilizations. A rotation system was in place and married men between the ages of twenty-five and thirty were required to join the army. During the reign of Huayna Capac and Tupac Yupanqui the army was at its height with approximately two hundred thousand men. Furthermore, not only would the Inca army do the fighting if an opposing force was taken, but the lead Inca would have the defeated soldiers fight with him. The best known Inca generals are Quizquiz, Chalkuchimac and Ruminahui, all generals of Emperor Atahualpa. Furthermore, Atoc was a general of Emperor Huascar. During the Inca reign the army was tested several times. To conquer the west of South America they had to fight many enemies. After successfully conquering Peru, the empire had many civil wars. One while Atahualpa was in power against his brother Huascar. This occurred between 1527 and 1532 and Atahualpa managed to conquer his brother and become the Inca leader. Also there were a few others during the reign of Huascar. The greatest test for the Inca army was to resist the conquest of the Spanish and Francisco Pizarro in 1528. This lasted until 1572. Pizarro managed to execute......half of a sheet of paper... a large stone or copper. It was cut to have six jagged sides for a strong blow to the side of the head and breaking enemy skulls. The armor worn by the Incas was next to nothing. Senior officers wore copper breastplate and shin guards when they were finally able to use copper and also had a helmet. Other men sometimes wore helmets, but most of the time the Inca did not use armor. The Inca army was an army known for its weapons, large numbers and warfare tactics. The Inca army could not resist the power of the Spanish conquistadors but could conquer any part of South America they wanted. The only reason the Inca fell from power was because of the Spanish and their more complex weapons. The Incas were not only one of the best empires of all time, but they also had one of the most powerful and best armies of their time.