Bologna was only for a short while subject to the Lombards, remaining generally under the rule of the exarchate of Ravenna, until this in 756 was given by Pippin to the papacy. It was sacked by the Hungarians in 902, but otherwise its history is little known, and it is uncertain when it acquired its freedom and its motto _Libertas_. But the first "constitution" of the commune of Bologna dates from about 1123, and at that time we find it a free and independent city. From the 12th to the 14th century it was very frequently at war, and strongly supported the Guelph cause against Frederick II. and against the neighbouring cities of Romagna and Emilia; indeed, in 1249 the Bolognese took Enzio, the emperor's son, prisoner, and kept him in confinement for the rest of his life. But the struggles between Guelphs and Ghibellines in Bologna itself soon followed, and the commune was so weakened that in 1337 Taddeo de' Pepoli made himself master of the town, and in 1350 his son sold it to Giovanni Visconti of Milan. Ten years later it was given to the papacy, but soon revolted and recovered its liberty. In 1401 Giovanni Bentivoglio made himself lord of Bologna, but was killed in a rebellion of 1402. It then returned to the Visconti, and after various struggles with the papacy was again secured in 1438 by the Bentivoglio, who held it till 1506, when Pope Julius II. drove them out, and brought Bologna once more under the papacy, under the sway of which it remained (except in the Napoleonic period between 1796 and 1815 and during the revolutions of 1821 and 1831) until in 1860 it became part of the kingdom of Italy. Among the most illustrious natives of Bologna may be noted Luigi Galvani (1737-1798), the discoverer of galvanism, and Prospero Lambertini (Pope Benedict XIV.). See C. Ricci, _Guida di Bologna_ (3rd ed., Bologna, 1900). (T. As.)