He moved on to Rome, becoming maestro di cappella to Francesco Maria Marescotti Ruspoli, 1st Prince of Cerveteri.

While there he wrote in 1710 La costanza in amor vince l'inganno (Faithfulness in Love Defeats Treachery) for the public theatre at Macerata.

With the unexpected death of Emperor Joseph I from smallpox at the age of 32 in April 1711, Caldara deemed it prudent to renew his connections with Charles III – soon to become Holy Roman Emperor Charles VI – as he travelled from Spain to Vienna via northern Italy.

Caldara visited Vienna in 1712, but found Marc'Antonio Ziani and Johann Joseph Fux firmly ensconced in the two highest musical posts.

He stopped at the Salzburg court on his return journey to Rome, where he was well received (and to which he subsequently sent one new opera annually from 1716 to 1727).