On June 18, 1541, Hernando de Soto's Spanish expeditionary force crossed the Mississippi River and became the first Europeans to enter Arkansas. For the next two years, the Spaniards explored through Arkansas with a large number of captive Indians. The expedition began on the gulf coast of Florida and for two years had explored what is now the American South. Its goal was to find a North American kingdom of gold on the scale of the Aztecs of Mexico, conquered by the Spanish twenty years earlier, but de Soto and his men instead found numerous well-populated villages supported by vast fields of maize. They had entered the Mississippian Period world, noted for mound-building and hierarchical political systems in which powerful chiefs controlled several villages that provided tribute to them. In Arkansas, de Soto encountered some of the largest villages, including Pacaha near Wilson and Casqui near Parkin in the northeast, and some of the most powerful chiefs in the South. The Spaniards killed numerous natives, consumed native food stores, and disrupted the region's political systems, weakening some and supporting others, though weakening was much more common. In northeast Arkansas, a de Soto chronicler described a 1541 attack by the Casqui on the temple of neighboring Pacaha in which Casqui destroyed relics of Pacaha ancestors entombed there. Mississippian culture was flourishing in eastern Arkansas when the expedition traveled through in 1541, but by 1673, when the next Europeans arrived to record their observations, the towns were gone, likely due in part to European diseases and severe, long-lasting drought in the 1500s.