Italy during the reign of Frederick Barbarossa. When Frederick conducted military campaigns in Italy to expand imperial power there, his supporters became known as Ghibellines (Ghibellini). The Lombard League and its allies were defending the liberties of the urban communes against the Emperor's encroachments and became known as Guelphs (Guelfi).
The Ghibellines were thus the imperial party, while the Guelphs supported the Pope. Broadly speaking, Guelphs tended to come from wealthy mercantile families, whereas Ghibellines were predominantly those whose wealth was based on agricultural estates.