Buenos Aires Founded: Spain Claims South America

Pedro de Mendoza arrived at the western shore of the Rio de la Plata in February 1536 with fourteen ships and roughly 2,500 colonists, the largest Spanish expedition to South America to that point. He named the settlement Santa Maria del Buen Ayre, after the patron saint of fair winds venerated by sailors from Sardinia. Within three years, the colony would be abandoned, its survivors starving and besieged. Spain in the 1530s was racing to replicate the staggering wealth Cortes had extracted from the Aztecs and Pizarro from the Incas. Rumors of a "Sierra de la Plata," a mountain of silver somewhere upriver, drew Mendoza south. Charles V granted him the title of adelantado and the right to colonize the vast region around the Rio de la Plata, hoping to block Portuguese expansion from Brazil. The settlers found no silver and no cooperative indigenous empire to exploit. The local Querandi people initially traded food but turned hostile when Spanish demands became excessive. Mendoza, already gravely ill with syphilis, ordered attacks that provoked sustained warfare. The colonists, cut off from resupply and unable to grow enough food, began to starve. Contemporary accounts describe desperate conditions. Some survivors reportedly resorted to eating leather, rats, and worse. Mendoza sailed for Spain in 1537 and died at sea. The surviving colonists abandoned Buenos Aires in 1541 and moved upriver to Asuncion, which had better relations with local Guarani communities. Buenos Aires was refounded in 1580 by Juan de Garay with settlers from Asuncion, and this second founding proved permanent. The city grew slowly for two centuries as a backwater of the Spanish Empire, overshadowed by Lima and Potosi. Its explosive growth into one of the world’s largest cities came only in the late nineteenth century, fueled by European immigration and the beef export trade.