In 1565 the Spanish established a colony in Florida at St Augustine to protect their more valuable colonies in the Caribbean and South America from any potential European rivals. After the destruction of a French outpost, Florida served the Spanish primarily as a military buffer between the Spanish Americas and other European colonies to the north. In addition, it acted as an important defensive bastion protecting the treasure fleets bearing the riches of the Americas to Spain. Because the Spanish population in Florida remained small, the extension of Spanish influence in the region was accomplished primarily through a chain of Franciscan missions. At their height, these missions encompassed tens of thousands of Indian converts and extended from the coastal islands of modern Georgia to the coast of the Gulf of Mexico. From its beginnings in 1565 through the first decades of the seventeenth century, the Spanish stubbornly maintained their presence in the south-east and Spanish missionaries, soldiers and traders ranging across Florida from St Augustine exercised enormous influence among the natives.

During the first decade of the seventeenth century England repeatedly began to defy Spain's claim to the region. The Spanish in St Augustine took careful note of the English efforts at Roanoke in the 1580s and the 1607 establishment of the colony at Jamestown.