The Spaniards soon came to a determination of colonizing this valuable acquisition, and to prevent any interference on the part of the other nations of Europe, Don Pedro de Mendoza was sent from Spain, and founded the city of Buenos Ayres, in 1535. From the early times of the colonization of this country till the establishment of a viceroyalty, the government was dependent on that of Peru; though the chief of Buenos Ayres had the title of captain-general. Buenos Ayres continued for a long time almost unknown, all the inhabited parts of the kingdom lying at a distance from the ocean, and by the restrictions put upon its commerce having no other communication with Europe than by the annual flota from Spain, it languished in indigence and obscurity: but the resources of so extensive and so fertile a territory could not remain for ever concealed; as the population, and, consequently, in an agricultural country, the riches increased, the constant remonstrances of the people at last opened the eyes of the Spanish government to the importance of the colony, a relaxation took place in the system of commercial monopoly which had been hitherto rigorously adhered to, and at last, in order to put a stop to a contraband trade that had been carried to an alarming height, register ships were allowed to sail under a licence from the council of the Indies at any time of the year. The annual flota dwindled away from 15,000 to 2000 tons of shipping, and, in 1748, they sailed for the last time to Cadiz, after having carried on, for two centuries, the trade of Spanish America. The register ships now supplied the market with European commodities at a cheaper rate, and at all times of the year; and Buenos Ayres became from that time a place of importance. Other relaxations in the mercantile system followed soon after: in 1774 a free trade was allowed between several of the American ports, and in 1778 seven Spanish sea-ports were declared free, to which in 1788, five others were added, and these were allowed an open trade to Buenos Ayres, and the ports of the Pacific. The city and the captain-generalship was now advancing with rapid strides into political importance; this was rendered stable by the erection of the government into a viceroyalty in 1778; and since that time its trade has progressively increased.