In 1608 Philip III. of Spain attended to the complaints that came to him through the powerful chiefs of the Order of the indifference and opposition shown by the settlers and colonial authorities, and gave his royal and official sanction to the Jesuit conversion of the Indians along the Upper Parana. By this time the Fathers had penetrated across to the Parana and had followed up that stream far north of the Grand Cataract in latitude 24 deg., which marks the northern boundary of Paraguay proper. It is hard to understand how they overcame the difficulties of travelling. To this day it is well-nigh impossible to reach the Grand Cataract, and years pass without that wonder of nature's being seen by the eyes of civilised man. No part of the world, outside the Arctic regions, is less accessible than the Parana above the Grand Cataract. Yet these heroic priests made that region the principal theatre of their operations in the early years of the seventeenth century. The territory is now all Brazilian,--the boundaries of that republic extend on the east bank of the Parana south nearly to the twenty-sixth degree and on the west bank to the twenty-fourth. The rivers Paranapanema and Ivahy are great tributaries coming down from the east between the twenty-second and twenty-third degrees, and draining a vast extent of the plateau that extends to the Brazilian coast mountains between Curitiba and Sao Paulo, and on their banks the Jesuits established their principal missions. In those days there were no clearly defined boundaries between the Portuguese and Spanish dominions. From 1580 to 1640 the king of Spain was also monarch of Portugal. The Jesuits held his royal letters patent for the conversion of the Indians of the province of Guayra--the name which this remote region bore. They had no reason to anticipate that they would be accused of being invaders of Portuguese territory, or that they would be interfered with by any Portuguese subjects of the Spanish Crown. The nearest Portuguese settlement was at Sao Paulo, from which Guayra could be reached only by the long and tedious descent of the Tiete River to its confluence with the Parana, and thence down that river to the Ivahy. Months would be necessary to make such a journey, great difficulties encountered with waterfalls and rapids, and great privations from want of food in the vast uninhabited regions on the route.