Colonia had long been a trouble to the Spaniards, diminishing their trade and insulting them by its propinquity, and in 1750 they made overtures for an exchange. The offending port was to be surrendered and the Portuguese were to receive in exchange a large portion of the Jesuit Missions, _i.e._, the territory called La Guayra and about 20,000 square miles to the east of the Uruguay River. This included seven Jesuit Reductions, and the Society and the Indians strenuously resisted the transference. Although the story of the Jesuits belongs rather to Paraguay than Argentina, it is for many reasons necessary to refer to that wonderful and benevolent despotism which they exercised in the Parana settlements, and also to relate the circumstances of their expulsion from South America--a matter of great importance to all the colonies. The Jesuits did not commence effective work in Paraguay earlier than the beginning of the seventeenth century. In the days of the conquest attempts had been made by them to convert the natives and to further general missionary work, but the circumstances had not been favourable. It was in 1610 that two members of the Order, Cataldino and Mazeta, founded the settlement of Loreto on the Upper Parana. An unfriendly critic[35] remarks: "They began by gathering together about one hundred and fifty wandering families, whom they persuaded to settle, and they united them into a little township. This was the slight foundation upon which they have built a superstructure which has amazed the world, and added so much power at the same time, that it has brought so much envy and jealousy upon their society. For when they had made this beginning, they laboured with such indefatigable pains, and with such masterly policy that, by degrees, they mollified the minds of the most savage nations,[36] fixed the most rambling, and subdued the most averse to government. They prevailed upon thousands of various dispersed tribes of people to embrace their religion, and to submit to their government; and when they had submitted, the Jesuits left nothing undone that could conduce to their remaining in this subjection, or that could tend to increase their number to the degree requisite for a well-ordered and potent society, and their labours were attended with amazing success."