The Spanish mission period began in 1633 when the first priests reached the Apalachee. Spanish documents of 1655 and 1675 record that there were between nine and eleven missions in Apalachee country. These missions stretched in a line from St Augustine (1565) on the Atlantic Coast to St. Louis, near the present city of Tallahassee.

The missions were built twenty miles apart or one day's ride by horse. St. Louis, or San Luis, was the administrative center for a number of smaller missions built westward toward the Apalachicola River.

The chain of missions crossed the Apalachicola River near Bloody Bluff and went on to Port St. Joe. It must be kept in mind that the entire Spanish Empire was laid out on a military pattern. The Castle of San Marco at St. Augustine and the Moro Castle at Havana, Cuba, protected on two sides the Straits of Florida. Through this passage travelled the annual treasure fleet from the New World with gold from Colombia and silver from Potosi, Bolivia.

The area around St. Augustine was expected to act as a granary for the city and castle in the manner of a Castilian armed city. The missions were a buffer zone or area of "pacification," both to serve as an extension of the granary and as an early warning system of any dangers from the English operating out of Charleston, S.C. (1670-1672) or Georgia.

The fort at St. Marks, Florida (1677), was intended to protect the mission chain from attacks by sea. This military arrangement had emerged not only from the victory by the Christian Spanish over the Moors in 1492, but also because it was Queen Isabella of an autocratic and militaristic Castile and not King Ferdinand of an easy-going Aragon who had financed Christopher Columbus.

The Spanish Empire was a Castilian Empire and tightly administered.