Fiéschi, Gian Luigi, conte di Lavagna, 1522-1547 ( the Younger) born c. 1522 died Jan. 2, 1547, Genoa [Italy] - Genoese nobleman, whose conspiracy against the Doria family is the subject of much literature. The Fieschi family was one of the greatest families of Liguria. Sinibaldo Fieschi, his father, had been a close friend of Andrea Doria and had rendered many important services to the Genoese republic. On his death in 1532 Gian Luigi found himself at the age of nine the head of the family and possessor of immense estates. In 1540 he married Eleanora Cibo, Marchesa de Massa.
While Andrea Doria had taken the side of the Holy Roman emperor Charles V, the Fieschi family adhered to the French or “popular” party in Genoa; the feud, rooted in the opposite political traditions of the two families, was said to have been aggravated by suspicions that Andrea Doria's son Giannettino was the lover of Fieschi's wife. When Fieschi conspired against Doria, he found friends in many quarters. Both Pier Luigi Farnese, Duke of Parma, and Francis I of France encouraged him. Among his associates in Genoa were his brothers Girolamo and Ottobuono, as well as Giovanni Verrina and R. Sacco. A number of armed men from the Fieschi fiefs were secretly brought to Genoa, and it was agreed that on Jan. 2, 1547, during the interregnum before the election of the new Genoese doge, the galleys in the port should be seized and the city gates held. The first part of the program was easily carried out, and Giannettino Doria rushed down to the port and was killed, but Andrea Doria escaped from the city in time. Gian Luigi Fieschi, while boarding one of the galleys, fell into the water and was drowned.
The news spread consternation among the Fieschi faction, and Girolamo found few adherents. They came to terms with the Genoese senate and were granted a general amnesty. Doria returned to Genoa on January 4 thirsting for revenge and, in spite of the amnesty, confiscated the Fieschi estates. Girolamo Fieschi and Verrina were captured, tried, tortured, and executed. Ottobuono Fieschi, who had escaped, was captured eight years afterward and put to death by Doria's orders.
The conspiracy has been treated in many poems and dramas, the most famous being Die Verschwörung des Fiesko zu Genua (1783; Fiesco; or, The Genoese Conspiracy) by Friedrich von Schiller.