In 1687, Giovanni Andrea sold the position of grand master to Francesco Farnese, the Duke of Parma, and thereafter lived as a castellan in Piacenza.

[7] As the last living male member of his family,[8] Giovanni Andrea became the Grand Master of the Constantinian Order of Saint George upon the death of his older brother, Girolamo II Angeli, in 1687.

Failed attempts were made to grant the position and the order to the Republic of Venice, Leopold I of the Holy Roman Empire and Gustav, Duke of Zweibrücken.

[10] Farnese was enormously wealthy, but hoped that the dignity of grand master, in the case of the Constantinian Order viewed as a potent symbol of royal status, would bring him greater prestige than his current rank as the ruler of two small duchies.

[11] To further cement his claim in the eyes of the nobility of Europe, Francesco produced a family tree showcasing his descent from the Byzantine emperor Isaac II Angelos through a female line, an actual genuine line of descent (though Francesco was far from alone in Europe as a female-line descendant of Isaac), though Farnese also embellished the genealogy by linking himself to Constantine the Great.

[15] Though some of the high-ranking members of the Constantinian Order initially opposed Farnese's accession, the confirmations by the Pope and the Holy Roman Emperor eased the transition of power.