The most powerful Native ruler the Spanish dealt with on this coast was not a chief of Tampa Bay at all, but the Calusa king the Spanish called Carlos, whose seat lay to the south. Yet Carlos belongs in this archive, because it was his ambition and his alliance with Pedro Menendez de Aviles that brought a Spanish garrison to the mouth of Tampa Bay in 1567, the first European outpost ever planted here, and because his story shows how the Spanish entered Florida not only by force but by tangling themselves in the existing wars of its peoples.
Carlos ruled the Calusa, the formidable fishing kingdom of southwest Florida, from his capital of Calos on Mound Key, in the Estero Bay country south of Tampa Bay. The Calusa were unlike the farming peoples to the north; they drew their wealth and power from the sea and the estuaries, and they dominated the lower Gulf coast so thoroughly that lesser chiefdoms paid them tribute and shipwrecked Spaniards lived among them as captives for years. Carlos was a proud and calculating ruler, and when Pedro Menendez de Aviles, the founder of St. Augustine, came to him in 1566 seeking the recovery of Christian captives and a foothold on the coast, Carlos saw an opportunity.
To bind the Spanish to him, Carlos offered Menendez his own sister in marriage. She was baptized Dona Antonia, and Menendez, though already married, accepted the match for the sake of the alliance and took her to Havana. Carlos's purpose was not surrender but strategy: he wanted Spanish power turned against his enemies, and chief among those enemies were the Tocobaga, the dominant chiefdom at the head of Tampa Bay. The marriage made the Calusa king and the Spanish adelantado, for a moment, partners.
In 1567 Menendez sailed north to Tocobaga territory at the head of the bay, carrying Carlos and a score of his warriors with him. Rather than make war, Menendez brokered a peace between the two great rival powers, recovered Christian captives and a dozen Calusa held as slaves by the Tocobaga, and, to hold the arrangement together, left a garrison of some thirty soldiers at the Tocobaga town on Tampa Bay. That garrison is the first European settlement known at the mouth of this bay, and it owed its existence to Carlos, whose feud with the Tocobaga had drawn the Spanish here in the first place. Within months it would end in disaster, the garrison found dead and the town abandoned.
The alliance did not last. Carlos grew disillusioned as the Spanish failed to deliver the conquest of his enemies he had wanted, and he was suspected of plotting against them. In 1567 the Spanish executed him. His death did not break the Calusa, who put up another chief and remained a hostile power on the Gulf for nearly two more centuries, long outlasting the Tocobaga and the other peoples of Tampa Bay. Carlos is remembered here as the ruler whose ambition, more than any Spanish plan, first brought soldiers to the bay's head, proof that the conquest of Florida ran along the fault lines of Native politics as much as along the edge of the sword.