Boii, a Celtic tribe, one section of which settled in Cisalpine Gaul around Bononia (Bologna, Italy) and another in what was later Bohemia, to which it gave its name. The Cisalpine group, after struggling against the Romans throughout the 3rd century bc, was subdued and made a Latin colony in 191 bc. The second group, which joined with another Celtic tribe, the Helvetii, to invade Gaul, was defeated in 58 bc by Julius Caesar. He allowed the survivors to settle in Gaul between the Liger (Loire) and Elaver (Allier) rivers. The remaining Boii south of the Danube River were exterminated by Burebistas of Dacia about 50 bc, and those in Bohemia were expelled by the Marcomanni tribe in 8 bc.