Pedro de Mendoza () (c. 1499 – June 23, 1537) was a Spanish conquistador, soldier and explorer, and the first adelantado of New Andalusia. Setting sail Pedro de Mendoza was born in Guadix, Grenada, part of a large noble family that was preeminent in Spain. His family settled in Guadix after its reconquest by the Christians in 1489. He was a page at the Spanish court of Emperor Charles V and accompanied the sovereign on his trip to England. In 1524 he received the title of knight of the Order of Alcántara and later, through the influence of his father — the knight Fernando de Mendoza Guadix — entered the Order of Santiago. He later fought in the Italian Wars against the French, in which he participated in the Sack of Rome in 1527. In 1529, he offered to explore South America at his own expense and establish colonies. Thanks to the efforts of his mother, María de Mendoza, in 1534 his offer was accepted: he was made adelantado governor, captain general, and chief justice over New Andalusia. This grant allowed him authority over as much land as he could conquer, within 200 leagues of the southern limit of New Toledo. Although this was measured along the Pacific coast, it was understood that his efforts would be directed towards the Río de la Plata on the Atlantic. The Emperor gave Mendoza 2000 men and 13 ships on the condition that within two years Mendoza should transport 1000 colonists, build roads into the interior, and construct three forts. He was to have half the treasure of the chiefs killed and nine-tenths of the ransom. The office of Governor was also, in theory, made hereditary. That year, he set sail with a considerable fleet, but a terrible storm scattered it off the coast of Brazil. Here his lieutenant, Juan de Osorio, was assassinated, according to some authorities by the orders of Mendoza himself because of suspected disloyalty. Mendoza sailed up the Río de la Plata in 1535 and founded Buenos Aires on February 2, 1536. Although Mendoza is said to be the founder of Rio de la Plata (and Buenos Aires), he was not a very effective leader because he was debilitated by a severe case of syphilis. He spent half of his time ill in bed, but he put as much effort as he could into the expedition. No notable campaigns