The expedition of Hernando de Soto to the current states of the Southeast, which pursued the same objectives as Juan Ponce de León, Lucas Vázquez de Ayllón and Pánfilo de Narváez, was an effort of conquest that with more than 600 men wandered throughout the Southeast of the United States in search of gold, silver and a passage to China from May 1539, when they disembarked in the area of the present Tampa Bay. De Soto died in 1542 on the banks of the Mississippi River. The Spanish soldiers brought death and diseases for the natives. When the expedition encountered hostile groups, their men often provoked confrontations. Equally devastating were the diseases that the members of the expedition transmitted. Because they lacked immunity, indigenous peoples suffered epidemics after contracting infectious diseases, such as smallpox, chicken pox and measles. Some areas visited by the expedition were depopulated by diseases caused by contact with Spanish soldiers.