The Aztec civilization
Around the 14th century, the Aztecs started off as a tribe of poor nomads in the Valley of Mexico, wandering in search of a permanent settlement. They lived by hunting or serving as mercenaries to wealthier tribes. Because of their ferocious nature and human sacrifice practices, the Aztecs were often treated as outcasts by the other tribes in Mexico.
It was only in 1325 when the Aztecs arrived at Lake Texcoco did they find a permanent place to settle down. According to Aztec tradition, their great sun god, Huitzilopochtli decreed that this swampy land at 7400 feet would be their permanent home. (It was said that an Aztec priest saw an eagle perched on a cactus, which he claimed to be a sign from Huitzilopochtli for the tribe to settle there.) The Aztecs began constructing a temple dedicated to their sun god and gradually built up their settlement around it. For survival, the tribe fished for food in the lake, hunted in the marshes, as well as traded with neighboring tribes.
Against such odds, the Aztec civilization began to grow into the city of Tenochtitlan within a few years. (Tenochtitlan means "the place of the prickly-pear cactus".) Subsequently, the warlike tribe began conquering their neighbors. Within the next century, they had successfully taken control of the entire Valley of Mexico and expanded their empire from the Gulf of Mexico to the Pacific Ocean.
In the Aztec empire, non-Aztec peoples basically served as servants or slaves to their Aztec masters. They had to send regular tributes (i.e. crops, artisan wares, luxury goods) to the Aztec capital of Tenochtitlan. Not only that, they also had to supply people as human sacrifices in the Aztec temples. It was said that the Aztec priests sacrificed between ten and fifty thousand people a year. (In 1473, when the twin temples to Huitzilopochtli and Quetzalcoatl, the creator of life, were dedicated, the priests worked day and night for four days to kill 20,000 victims. )
At the bottom of the social strata were the slaves. Just above them, but not necessarily much better off were the mayeques, who were officially free men. However, due to extenuating economic circumstances, they were often forced to live a life of bondage. Renting land from nobles or priests, the mayeques had to give up most of their crops as rent.
The next social level was the free commoners, who lived in slightly better-off conditions. They could be farmers or artisans plying their trade to make a living. It was mainly their taxes that formed the bulwark to support the government and social services. Above the commoners were the pilli (aristocratic class) who formed the majority of the tecuhtli (the ruling class in Aztec society). Examples of the tecuhtli included government officials, military officers, judges and nobles. Not only did the elite class not have to pay taxes, they were also given many perks like fine houses and land.
There was also little social mobility within the Aztec society. Children would usually follow their fathers in their respective trades. The purpose of education was also to train the Aztec for his designated role as determined by custom and tradition.
Because of the strict discipline imposed at home and at an early age, the Aztecs were obedient towards authority. From young, they were taught to obey the king, the priests, the law, their elders and above all, the Aztec gods.
The Aztecs firmly believed that their Sun god, Huitzilopochtli, required daily offerings of human heart and blood. If not, they feared that the sun would not rise again the next day. With the sun, crops would grow and life could continue as before. According to Aztec beliefs, if Huitzilopochtli and the other gods were angry with them, the world would come to an end. They also believed that Huitzilopochtli had promised that they would be a master race, and that non-Aztecs only existed to serve them and be their religious sacrifices.
The Aztecs also believed that demons and ghosts were everywhere. Superstition ran deep in the Aztec psyche. They would refuse to construct buildings, go to war, go on trade missions, get married or do anything important until the priests had consulted the stars to propose a favorable time and date.
The Aztecs did not use the wheel or even animals for basic transport. They mainly relied on humans (essentially slaves) to carry goods, draw the ploughs and other manual chores. While the Aztecs were aware of the use of metals, they mainly used them either as personal ornaments or decorating buildings and temples.
On the other hand, probably due to their system of belief, the Aztecs' knowledge of astronomy was actually more advanced than that of the Europeans at the time. Aztec astronomers, who were priests, already knew how to plot and chart the movements of the sun, moon and other planets. Their observations were recorded in the form of geometric and mathematical symbols.
Relations with other tribes
Given their aggressive tendencies and warlike inclinations, the Aztecs were greatly feared and hated by the other tribes. As the Aztecs viewed tribes that refused to trade with them as enemies, they were often prepared to start a war to force the others to engage in trade with them. In addition, the other tribes were fully aware that the Aztec traders often served as spies who would gather information about the economic and military conditions which were then reported to the Aztec king. If the Aztecs assessed that it was worth their while, they would send in their troops to conquer the tribe.
Over many battles, the Aztecs acquired a fearsome reputation of being excellent soldiers, who were also well-equipped with effective weapons like razor-sharp swords, javelins and arrows. Aztec soldiers wore a thick padded cotton suit as their armor while they also carried a shield during battles. A common fighting tactic used by the Aztecs was to create frightening noises (using drums and whistles) to scare their opponents at the onset of a battle.