The Dunsirn were assimilated into Clan Giovanni in the early 18th century. Before that, the Dunsirn were already a rich family. Rumors speak that the patriarch of the modern Dunsirn was banished from his family's estate for the crime of cannibalism. Unperturbed, the outcast returned with a family of his own, killed (and probably ate) his relatives and overtook their business. In the modern family, cannibalism is treated like an urban legend, and many Kindred that have contact with a Dunsirn banker joke about it, but just as many still look wary when a Dunsirn eats a sandwich.
It is believed that the Dunsirn entered service to the Giovanni with a loophole of leaving the Clan when they desired it. Not interested in Necromancy, the family focuses nearly exclusively on making money. The Dunsirn were crucial for establishing Giovanni domains in the colonies, and their influence in the U.K allowed them to play on the various internal conflicts, like the issue between Protestants and Catholics in Ireland. In modern times, the Dunsirn have been vital for the developments of Giovanni interests in the European Union. However, several Anziani now insist that the Dunsirn have to deepen their knowledge of Necromancy in the wake of the Sixth Maelstrom. Being bossed around chafes at the Dunsirn's pride and some worry what this will bode for the relationship between the families.
Another facet of the Dunsirn is that they are distantly related to Garou (i.e. some of them are Kinfolk), understood to be Fianna (although given their location in Scotland, it could also be one of the old Kin lines of the Black Spiral Dancers). Approximately, one in hundred children has the potential for the First Change and in the rare case that the child becomes a Garou, it is either quickly killed by the family or flees to become a Ronin. Also, more Dunsirn than any other family are adept in Hedge magic, which is tolerated by the main family.