A large number of prehispanic and colonial indigenous texts have disappeared over time. For example, when Hernan Cortés and his six hundred conquistadores landed on the Aztec land in 1519, they found that the Aztecs kept books both in temples and in libraries associated to palaces such as that of Moctezuma. For example, besides the testimony of Bernal Díaz quoted above, the conquistador Juan Cano describes some of the books to be found at the library of Moctezuma, dealing with religion, genealogies, government, and geography, lamenting their destruction at the hands of the Spaniards, for they such books were essential for the government and policy of indigenous nations. Further loss was caused by catholic priests, who destroyed many of the surviving manuscripts during the early colonial period, burning them because they considered them idolatric.