A personal example illustrates the importance of understanding Jewish given names in Jewish genealogical research. My grandfather had a first cousin, who was listed by various names in different sources. The first document, illustrated here, is his 1881 civil marriage registration from Nowogr�d, Lomza Guberniya, Poland, which lists him (in Cyrillic letters) as "Leibka Gershkevich". In Russian, this means "Leib, son of Hersh".