Many Ostfriesian surnames are patronymical in origin.
While patrynomics was not unique to Ostfriesland, it does present research challenges. Patronymics was used Ostfriesland until the early part of the 19th century, when the patriarch of each family was to choose a permanent surname for his descendants. However, some families continued this practice for several years afterwards. There were some families however, who continued until the mid-1800's, especially in the use of middle names. This constant changing of surnames can create confusion, however.