The first siege, in August, resulted in the destruction of the town, but Fort San Carlos de Austria successfully resisted the onslaught.

Pensacola's governor, Don Sebastián de Moscoso, whose garrison was depleted by disease, recruited convicted criminals to assist in the fort's defense.

English and Spanish colonies in southeastern North America began coming into conflict as early as the middle of the 17th century.

Since its founding in the 16th century, the Spanish had set up a network of missions whose primary purpose was to pacify the local Indian population and convert them to Roman Catholicism.

[1] By the early 18th century, Carolina traders like Anthony Dodsworth and Thomas Nairne had established alliances with Creek Indians in the upper watersheds of rivers draining into the Gulf of Mexico, who they supplied with arms and from whom they purchased slaves and animal pelts.

[7] A French-organized 1706 expedition against Charles Town was a failure but motivated Carolina authorities to again target the Spanish at Pensacola and the French at Mobile.

[8] Nairne proposed a major expedition after the attack on Charles Town, intending to recruit as many as 1,500 Indians to capture Mobile, but political divisions in Carolina prevented execution of the plan.

[12] Extant records do not describe the composition of the forces that attacked Pensacola in August beyond "several hundred Tallapoosas and a few South Carolina traders".

[15][16] On that day, a Carolinian (unidentified in Spanish reports, but possibly Thomas Nairne) brought a demand for surrender written in English.

[15] The besiegers began an ineffectual attack on the fort around midnight which lasted until daybreak, at which point they delivered a final surrender demand which Moscoso again refused.

In order to supplement his forces, he successfully recruited convicts being held in the fort's guardhouse to participate in the defense, offering them freedom and money for their service.