Guglielmo Boccanegra was a Genoese statesman, the first capitano del popolo of the Republic of Genoa, from 1257 to 1262, exercising a real lordship, assisted in the government by a council of 32 elders.

[1] He is first securely attested in 1249, as one of the Genoese consuls at Aigues-Mortes (the main embarkation port for the Crusade), while in 1249–50 he was at Acre, where he undertook to pay salaries to the followers of Alphonse of Poitiers, Louis IX's younger brother.

[1] When Frederick II died in 1250, the Guelph nobles prudently allowed the exiled Ghibelline opponents to return to the city, and even gave them some compensation, in an effort to strengthen the nobility's position against the common people.

[1] This policy was helped by the economic boom experienced during the 1250s: despite constant military commitments overseas, trade expanded, leading to an influx of bankers and money-changers, as well as artisans, from other parts of Italy and France.

[1] At the same time, the newfound wealth was unevenly distributed, accruing mostly to the hands of a few noble merchant families, and both popular discontent and the Guelph–Ghibelline divide continued to simmer beneath the surface.

[1][3] Domestically, the government had to enforce a Papal ordnance against heretics, while abroad, Genoa's position in Sicily and the Levant suffered setbacks, with the outbreak of the War of Saint Sabas against the Republic of Venice.

[1] It was this atmosphere of crisis that Boccanegra came to the fore, but why exactly remains a puzzle; as the historian Steven Epstein comments, his recorded career until this point was unexceptional.

[1] His position was further strengthened when Cardinal Ottobuono Fieschi, who had arrived under the pretext of a diplomatic mission, but in reality to stir up opposition against him, was forced to leave the city after the people rioted.

Boccanegra was loath to raise new indirect taxes, so with a decree issued on 16 June 1259, he converted all public debt into a consolidated and redeemable loan, at a modest and fixed interest of eight percent.

[1] This measure, which was sworn to by both the popular assembly and prominent Ghibelline nobles, not only hurt many magnates, but also gave Boccanegra the funds necessary for an expansionary fiscal policy.

[1] At the same time, he successfully strove to eliminate many feudal taxes levied by the Malaspina marquesses and other lords of the Ligurian countryside, that pre-dated the establishment of the Genoese Commune; he purchased at a favorable rate the rights of the Archbishopric of Genoa on maritime trade; and tried, without success, to eliminate the taxes levied by a few noble families as part of their inheritance from the now-abolished viscounts of the region.

The treaty obliged Genoa to furnish a fleet of 50 vessels, with their expenses paid by the Emperor, for service against Venice and in support of Palaiologos' aim of recovering Constantinople.

Nevertheless, Michael VIII scrupulously observed the terms of the Treaty of Nymphaeum, as Genoese naval strength was still necessary to confront a potential Venetian counterstrike while a native Byzantine fleet was slowly being re-established.

[10] Nevertheless, the memory of Boccanegra's rule was controversial: the annalists, who represent the interests of the city's elites, treat him with hostility,[2] but the common people soon grew nostalgic for a "popular" government.