Maffeo's father, Taddeo, and Luigi Mattei led the papal armies loyal to Pope Urban VIII and the Barberini family.

The Barberini, too, were keen to return to Rome and were enthusiastic about Maidalchini's plan to marry Pope Innocent's grand-niece, Guistiniani, into their family.

Her mother, who had barely been involved in her upbringing, appealed to her by telling her that other girls were forced to marry decrepit old men and that, by comparison, Barberini was a far better option.

[4] The king agreed, despite potential claims from Colonna descendants, and gave Maffeo permission to take control of a series of comunes including and Petrella Salto.

Barberini was also given permission to take control of the comune of Torre Annunziata which had been owned by the Orsini family but had been seized by the Spanish Treasury several years earlier.

In 1653, Barberini reopened the Teatro delle Quattro Fontane after it had been closed for more than 10 years while his uncles and father had been in exile.