Carlos ruled over one of the most powerful and prosperous chiefdoms in the region at the time, controlling the coastal areas of southwest Florida and wielding influence throughout the southern peninsula.

At this time, Carlos faced internal political pressure from Felipe as well as war with external enemies, most notably the Tocobaga around Tampa Bay.

[1] The Calusa did not practice substantive agriculture, but the abundant supply of fish and shellfish in their territory supported their large, sedentary population.

The chief's power derived from their paramount place in the Calusa religious system as well as their ability to control and distribute trade goods.

This interpretation is based on Carlos' succession controversy, which suggests that power was at least partly vested in the institution of the throne rather than a hereditary line.

[5] Carlos inherited the chiefdom from his father and predecessor, whose name was given as Senquene by shipwreck survivor Hernando de Escalante Fontaneda, a prisoner of the Calusa from about 1549 to 1566.

As the Calusa, unusually among Southeastern peoples, apparently practiced patrilineal succession, the king named Felipe his heir.

In 1556, the daughter of Oathchaqua, chief of the Ais of Cape Canaveral, set out for Calusa to cement an alliance between their peoples by marrying Carlos.

In doing so, Chief Surruque challenged Carlos' authority, disrupted the key alliance and trading route between the Calusa and Ais, and positioned himself as a significant power.

A few years later, the Tocobaga of Tampa Bay asserted themselves by capturing twelve Calusa nobles, including the sister of Carlos' wife.

[13] Menéndez' primary goal in the voyage was to secure the release of Spanish shipwreck survivors living among the Calusa, including his son Juan.

He also may have hoped it would give him the upper hand in his rivalry with Felipe, whom the Spanish chronicler Gonzalo Solís de Merás wrote was even more feared by his people than Carlos himself.

He allowed the Spanish to establish a small outpost and a Jesuit mission, San Antón de Carlos, near the main town of Calos.

Reinoso wanted to fight back, but was prevented from doing so by Father Juan de Rogel, who led Mission San Antón.