Giambattista Costaguti was born in
Rome in 1636, the son of Prospero Costaguti,
marquis of
Sipicciano (a member of the
Genoese nobility) and of his second wife Rocca Elvezia, Countess Vidman. He was the younger half-brother of
Vincenzo Costaguti, who became a cardinal in 1643. Costaguti entered the church as a young man, serving as a clerk in the
Apostolic Camera, and rising to become its
dean in 1669. In the
consistory of February 13, 1690,
Pope Alexander VIII made him a
cardinal priest. On April 10, 1690, he received the
red hat and the
titular church of
San Bernardo alle Terme. He participated in the
papal conclave of 1691 that elected
Pope Innocent XII. He opted for the titular church of
Sant'Anastasia on November 12, 1691. He later participated in the
papal conclave of 1700 that elected
Pope Clement XI. He died on March 8, 1704 and is buried in
San Carlo ai Catinari. ==References==