The Department of Archaeology at Stockholm University has 1978-87 carried out seminar excavations at the cemetery Raä 16, Söderby, on Lovö, located west of Stockholm. The cemetery consists of 28 (29) graves dated to 550-850 AD. A model for inheritance in a nuclear family, tested on the material, shows that a nuclear family consists of 3-6 individuals. Söderby farm has four cemeteries from Late Iron Age. They can be interpreted as separate family cemeteries from the population who lived at the Söderby village.