GIAMBELLI or GIANIBELLI, FEDERIGO (fl. 16th century), Italian military engineer, a native of Mantua, who, during the siege of Antwerp by the duke of Parma in 1584. put himself in communication with Queen Elizabeth, who engaged him as an adviser in the defence. The senate agreed to a modifica tion of his scheme for destroying the bridge which closed the entrance to the town from the side of the sea, by the conversion of two ships of 6o and 7o tons into infernal machines. One of these exploded, killed more than i,000 soldiers, effected a breach more than 2oof t. wide, by which, but for the hesitation of Ad miral Jacobzoon, the town might at once have been relieved. After the surrender of Antwerp Giambelli went to England, where he fortified the river Thames; and when the Spanish Armada was attacked by fireships in the Calais roads, the Spaniards were per suaded that the fireships were infernal machines constructed by Giambelli. He is said to have died in London.