 He arrived at the mouth of the River May on June 22, 1564, sailed up it a few miles, and founded Fort Caroline.Desiring to protect its claimed territories in North America against such incursions, the Spanish Crown issued an "asiento" to Menéndez, signed by King Philip II on March 20, 1565, granting him expansive trade privileges, the power to distribute lands, and licenses to sell 500 slaves, as well as various titles, including that of "adelantado" of Florida.This contract directed Menéndez to sail for "La Florida", reconnoitre it from the Florida Keys to present-day Canada, and report on its coastal features, with a view to establishing a permanent settlement for the defense of the Spanish treasure fleet.