Of these tribes the Aztecs and Tezcucans were superior to the Tlacopans. Spoils of war were always divided into five portions. The Tlacopans took one, their allies shared equally the other four parts. The Indian pueblos generally were designed to withstand a protracted siege, but the Mexican pueblos were almost impregnable. It is not likely that any other Indian tribes could have captured them. Dwelling securely in these great communal houses, which were also fortresses, the Aztec confederacy held many other tribes in subjection. It was only necessary for it to send its agents to other pueblos to secure at once the specified tribute. Failure to pay this tribute brought summary punishment at the hands of the warriors of the confederacy. The “empire” was “only a partnership formed for the purpose of carrying on the business of warfare, and that intended, not for the extension of territorial ownership, but only for an increase of the means of subsistence.” The subject peoples were never incorporated into the confederacy. The tribe remained intact. The houses the tribe occupied were common property, and so was the land cultivated. Neither land nor houses could be sold, and as the tribe increased in numbers new communal houses were built to accommodate the increase. The great fortress-dwellings in a, for savages, well-cultivated land prevented the subdivision of tribes which was constantly taking place in wilder North America. Twenty clans, organized into four phratries, made up of the Aztec tribe. The clans were called “calpullis.” They were governed by a council of chiefs, “tecuhtli,” elected by the clan. There was an official head, the “calpullac,” whose duties were mainly civil, and also a military leader, the “ohcacautin” (“elder brother”). Painful religious ordeals accompanied the initiation of these men into office. Clan officers held their places during good behavior. Medicinemen, or priests, were members of the clan council. To the four phratries into which the clan was divided four quarters of the city of Mexico, each under its own captain, were assigned. Their titles were “man of the house of darts,” “chief of the eagle and cactus,” “blood-shedder,” and “cutter of men.” Of these captains the “chief of the eagle and cactus” was chief executioner. Their principal duty was to maintain order both within and without the pueblo. In each of these four quarters was an armory (“house of darts”), in which the weapons of the phratry were kept when its warriors were not engaged in warfare. The phratry was in Mexico primarily a military organization.