Abstract This article deals with the discussion of the Eastern European family and forms of patriarchalism as an ideological base for families. Changes in the patriarchal families in Eastern Finland will be examined as a process from the pre-Christian period until the 19th century. Eastern Finnish families were situated on the classical European/non-European family forms border area. By comparing families of Eastern Finland with those of the Balkans and Russia, strict principles of patriarchalism, patrilineality, and patrilocality common over a wide area can be discovered. The demography and economy influenced the existence and rate of joint families, but did not necessarily change the patriarchal principles of the family until major transformations in family organization began in the late 18th century. Housing and inheritance practices, folklore, wedding customs, ancestor worship, and blood vengeance reflected the importance of kin, seniority, patrilineality, and patrilocality in social organization.