In the days of the Spanish conquest, Franciscan monks were the priests who most often accompanied the expeditions, and they took the most prominent part in the earliest establishment of religion. The members of this Order, however, with a few notable exceptions, took no special interest in the evangelisation of the aborigines. On the contrary, they were as fierce as the soldiers themselves in their cruelties to the poor Indians. The shouts of a Franciscan monk set on Pizarro's ruffians to the slaughter of the Incas that surrounded Atahualpa. Those that came to Paraguay preferred to live in the towns, and their conduct toward the Indians differed little from that of the lay Spaniards. It was the genius of Ignatius Loyola that conceived and perfected a machine able to carry Christianity and civilisation to these remote and inaccessible peoples and regions. Within a few years after its foundation, the Society of Jesus turned its attention to the evangelisation of South America; in 1550 the Jesuit Fathers began their work in Brazil. Their successes and failures in that country had little relation with their work in Spanish South America. It is curious, however, that their most successful early work in Brazil should have been done in Sao Paulo, on the extreme eastern border of the wide plateau which drains to the west into the Parana. For a decade or two after 1550, they laboured hard to gather the Indians of that region into villages, to teach them Christianity, and protect them against the tyrannies and exactions of the Portuguese settlers. The contest was unequal; the Jesuits were not long able to prevent the enslavement of their proselytes. The Paulistas destroyed the Jesuit missions in their neighbourhood and became the most expert in Indian warfare and the most terrible foes of the Jesuit system of all the colonists of South America. Their determined opposition was the most potent cause in preventing the subjection of South America to a theocratic system of government.