Shortly after the sacking of Mexico by the Spaniards, the leaders of New Spain heard many rumors of the riches existing in the vast area north of Mexico. In both 1540 and 1599, the viceroy of Mexico formed very large armies to march to the north and find and loot the wealth from areas reputed to being very rich. Francisco Coronado headed the first expedition, but in Cibola and Quivira found the Indians to be very poor and living in skin lodges. Coronado returned to Mexico in great disgrace. Despite the Coronado failures, the Spanish leaders still believed that Quivira possessed rich gold mines. They commissioned Juan de Onaté to lead another expensive expedition to investigate the area. Upon reaching Quivira, Onaté met the same fate as Coronado. He found no gold and had to retreat in ignominious defeat. In spite of the failings of Onaté, the men of his expedition had a great interplay with the Indians of Quivira. On one occasion, they helped defend the Pawnee Indians from the Comanche tribe. So great was the Spaniard quest for gold, that 180 years after Coronado, the Spaniards under Don Pedro de Villasur again invaded Quivira. At this late date under the influence of the French, the Oto and Pawnee attacked the Spaniards along the Platte River and decimated their army. This defeat then spelled the end of the Spanish power on the Great Plains.