Background
She was the granddaughter of Olimpia Maidalchini, grand-niece of Pope Innocent X and wife of Maffeo Barberini, Prince of Palestrina. Guistiniani was born on May 18, 1641 at the Palazzo Pamphili to Andrea Giustiniani and Anna Maria Flaminia Pamphili, of the powerful Giustiniani and Pamphili families. Olimpia Guistiniani was married in 1653 to Maffeo Barberini, son of Taddeo Barberini (who died in exile in Paris), future Prince of Palestrina and heir to the Barberini estate.
