The Lamberg family appeared in Carniola in the second third of the fourteenth century. Their fertility and shrewd political acumen paved the path to their social ascension and territorial expansion. By the sixteenth century, they had made their way into the most prominent offices in the administration of the Carniolan provincial estates. One of the most competent representatives of the family was Baron Jakob from the Kamen line, who is believed to have written the first family genealogy in 1559. This document, combined with another contemporaneous record, became the main source for future genealogists and historians who uncritically copied it, including the erroneous data that are presented, explained, and corrected in the contribution at hand. Then follows the biographical presentation of the family based on preserved sources. The article also presents the members of the family of ministeriales from Rittersberg, who were presumably the predecessors of the Lambergs.