The Spanish claim to territories that are today the United States rested upon the 16th century exploits of Ponce de León, Hernando De Soto, and Francisco Vázquez de Coronado. St. Augustine in Florida was established as a Spanish fort in 1565, the first permanent settlement in what would become the United States. The impact of this settlement was slight, however, since it served primarily as a base camp for other exploratory ventures and also as the center of efforts to convert the area's natives to Roman Catholicism. A handful of Spanish settlements was established in outlying areas, but they soon fell prey to Indian attacks or economic insufficiency. Greater progress was made by Spanish colonizers on the other side of the continent. In 1598, Don Juan Oñante led 500 men from Mexico northward into Pueblo lands in present-day New Mexico. The invaders brought with them a labor system known as the encomienda, which had originally developed in Spain. Under this scheme, large New World land grants were made by the Crown to favored Spanish individuals. The grantees were responsible for the protection and Christian instruction of inhabitants of the lands, and those natives were required to pay tribute — often in the form of crops and labor — to the grantee. Understandably, the Pueblo deeply resented the entire system — invasion of their lands, suppression of their religion, payment of tribute, and enforced loyalty to a foreign monarch. The encomienda was used throughout Spanish America. Its application differed sharply from one area to another, being relatively benign in some regions, but virtually enslaving in others. Reform of the system was sought by a Spanish missionary, Bartolomé de Las Casas. Oñante, fired by a passion for precious metals, launched a series of explorations eastward into present-day Kansas and Oklahoma, and westward to the Gulf of California. In some instances, he retraced Coronado's steps and was equally unsuccessful in discovering gold and silver. New settlements were erected at Santa Fe in 1609 and nearby Taos in 1615. Relationships between the colonists and the Pueblo improved as they cooperated in livestock raising (mostly cattle and sheep), but an undercurrent of resentment remained strong. In 1680, a major revolt broke out under native leader Papé. Hundreds were killed on both sides in the fighting and order was not restored until 1692. As the 17th century drew to a close, Spanish colonial administrators finally realized that, given their minority status in so many parts of New Spain, policy reform was necessary. In the coming years, the Pueblo were allowed to resume the practice of their religion, own land, and be free from forced labor. From a material standpoint, the Spanish ventures in the northern portions of their realm were far less successful than those to the south.