Decio Azzolini

Decio Azzolino (11 April 1623 – 8 June 1689) was an Italian Catholic Cardinal, code-breaker, investigator and leader of the Squadrone Volante.

Azzolino was born at Fermo, the son of Pompeo Azzolino and Giulia Ruffo. He was the great-nephew of Cardinal Decio Azzolino, the elder and is thus often referred to as Cardinal Decio Azzolino, the younger.

He received doctorates in philosophy, law and theology from the University of Fermo.

In January 18, 1642 Pope Urban VIII named Bishop Giovanni Giacomo Panciroli nuncio extraordinary to Spain. Azzolino followed Panciroli to Madrid, and in 1644 when Pope Innocent X appointed Panciroli Secretary of State, he began assisting him in the Secretariat. When Panciroli died in September 1651, Azzolino managed the Secretariat until the return of Bishop Fabio Chigi from Germany. Chigi was named Secretary of State in December.

Azzolino was a skilled cryptographer, responsible for cracking ciphers used in correspondence. He was also an able investigator. When the Kingdom of Naples was made aware of invasion plans by Henry II, Duke of Guise, it was Azzolino who (in February 1654) concluded that the breach must have come from Camillo Astalli, the Pope's Cardinal-Nephew. Though likely accurate, his conclusion was convenient - Astalli was a rival for power to Azzolino's own patron, Olimpia Maidalchini. Contemporary John Bargrave noted that there were plenty of spies within the Vatican but that none excelled at the task more than Azzolino.

...
Wikipedia