The Guelphs were a political faction in Italy active from the 12th century. The Guelphs supported papal power within Italy, as opposed to the Gibelines who supported the Holy Roman Empire.
Ascendancy over the Ghibeline faction in the late 13th century saw the faction splinter in Florence. These two sub-factions were the black guelphs, who continued to support the papacy, and the white guelphs, who wanted neither an Emperor nor a Pope.
As a general rule, Guelphs came from wealthy mercantile families. Supporters of the Guelph faction would often add a capo d'Angio to their device in order to show their allegiance.