Over the course of his various administrative appointments, Benavides apparently donated most of his income to the poor people of Florida, Yucatan, Veracruz and Santa Cruz de Tenerife in the Canary Islands.

In late 1698 a captain of the Bandera de la Habana (Flag of Havana) stayed at the Benavides family home while touring the island to recruit young men into the Spanish army for service in the New World colonies.

Due to Benavides' exceptional skill as a marksman and the friendship that had developed between them, the king ordered him to be enrolled in the Corps – an unusual circumstance, since normally only the children of the nobility could join.

On 20 August 1710, he commanded a Guards of Corps cavalry squadron of the Bourbon Spanish forces in the Battle of Saragossa, and managed to seize the enemy's artillery in a surprise attack.

[14][15] Philip V, wanting to utilize his services and repay his steadfast loyalty, appointed Benavides governor and captain general of Florida while he was convalescing in Tenerife from his previous injuries.

[18] Meanwhile, the British had founded Charles Town in 1670 in Carolina, on territory the Spanish claimed, and with good reason considered St. Augustine the greatest threat to their security.

[19] Under the previous administration of interim governor Juan de Ayala y Escobar, the territory of La Florida had been attacked frequently by these restive tribes and the British, who continued to harass the Spanish, hoping to hinder their trade and force them to abandon the province.

In his periodic official reports to the king, he countered complaints from the disaffected and their possibly distorted interpretations of his actions, informing him of the colony's status and explaining what reforms were needed.

[26] Benavides wrote the king that by repopulating the country with settler families and dispatching five hundred soldiers to refortify it, Spain might reclaim its lost territory.

He also proposed the creation of a line of presidios along the Gulf Coast from Veracruz to Apalachee to protect the overland route, and eventually allow the development of a profitable coastal trade.

[35] Perhaps fearing the possibility of reprisal, in 1725 Benavides sent a delegation to Charles Town with an offer to purchase 10 fugitive slaves who had fled to St. Augustine, for 200 pesos apiece.

In 1726, Benavides' term of office was temporarily interrupted when he went to Havana to be operated on for appendicitis; Ignacio Rodriguez Rozo served as interim governor in his place.

[48][49] Also in 1733, Benavides proposed sending the runaways to Carolina to incite a rebellion, again intending to "pay them for English scalps", but the Council of the Indies declined to approve this action.

Before he left the province, the king promoted him to the rank of Field Marshal for his able execution of the duties of his office,[9] and as a parting gesture, he donated his belongings to the needy citizens of Florida.

[52] After many years of service to the crown, Benavides began to feel that he should leave governance, and desiring not to harm the interests of the colony, asked to be released from office, but Ferdinand VI refused.

[53] In 1745, he requested that the Crown create the new position of Teniente de Rey (King's Lieutenant) in Campeche, in the Captaincy General of Yucatán, to ensure a continuous military command in the main port of the province, which was a target of frequent attacks by British privateers and buccaneers who roamed the seas off its coast.

Having someone occupy this position would ensure an automatic succession to the office of Governor and Captain General of Yucatán, until a final appointment could be made by the king or the viceroy.

This decision was popular among the citizens of Campeche, but not with those of Mérida, whose alcalde in the city council had previously held the status of presumptive replacement of governors who vacated their office.

Having acquired the rank of Lieutenant General of the Royal Armies, he commanded an expedition formed to defend the coast of Tabasco and Honduras in the War of Jenkins' Ear (1739–48).

He led a small army of regulars, reinforced by the peasant militia, with orders to defend the coasts of Honduras and Tabasco, and to protect the ports chosen to supply the ships of the Royal Spanish Navy.

Governor Benavides made a proposal to the Spanish Crown for the creation of a fund to compensate the poorly paid military personnel garrisoned in Campeche, to be financed with the income of the vacant encomiendas.

[55] This caused great consternation among the "encomenderos" of the province, who saw it as jeopardizing their income and prerogatives in favor of the militia; they believed the governor had betrayed the interests of the wealthy families who enjoyed the privileges of the encomiendas.