He was the son of Francisco Paim Câmara and D. Isabel de Sousa Neto, from noble families linked with early colonization, and involved in the governance of the village (later Captaincy) of Praia.
On returning to Terceira, King Philip III of Portugal, by royal charter (dated 15 September 1636) he was nominated as the Captain-major and provisioner of the fortifications of Praia, positions that his father exercised 30 years previously.
Through intermediaries, he tried to make an accord with the Castilian governor, Field Master D. Álvaro de Viveiros, offering him the title of Count and 10,000 cruzados for him to surrender the fortress in Angra.
D. Álvaro de Viveiros who, since 1627, was the military governor at the fortress, realized that the local population was turning against the Castilian forces, and prepared the defences, stockpiling ammunition and foodstuffs for a blockade.
Although popular news, the notice of John IV's acclamation in Lisbon had left the nobility and Angran elites with trepidation as to their future, fearful of a repeat of the bloodbath that occurred following the disembarkation in the bay of Mós in 1583.
On 24 March 1641, which fell on the Palm Sunday, following mass, in the Santa Cruz churchyard, Francisco Ornelas acclaimed John IV as King of Portugal, swearing fidelity and allegiance.
The news of the proceedings circulated throughout the island, and days later, in Angra, António do Canto exclaimed in public the same cry to the new King, raising an agitation in the citizenry and causing some Spanish reactions.
João de Bettencourt was nominated governor and Captain-major of Angra, swearing allegiance to and declaring the supremacy of King John IV, on 31 March in the Sé Cathedral.
Meanwhile, attempts to communicate by sea with Spain succeeded, and by summer, a nau commanded by D. Luiz de Viveros (the military governor's brother), disembarked troops in the promontory of Santa Catarina.
As summer arrived, with water reserves low, hope of a reinforcements by sea disappearing, and with famine and death spreading, D. Álvaro de Viveros capitulated on 4 March 1642.
When he arrived in Lisbon, he was received by Queen D. Luísa de Gusmão, then regent in name of her son (the futuro Afonso VI of Portugal, who recognizing his loyalty, spoke on her great appreciation.