Surname law matronym from the name of a parent or parent-in-law; these possibilities are not necessarily open to native Icelanders. Reza Shah Pahlavi ordered Iranians to adopt Western style surnames in place of old Islamic names and titles during his reign. A law in Japan dating from 1896 requires a married couple to have a common surname. Most commonly it was the wife who took her husband's name. In 2011, this law was challenged as unconstitutional on gender equality grounds, but the Supreme Court of Japan upheld the law in 2015. Prussia tasked the implementation of surnames to E. T. A. Hoffmann.
One-name study One-name study A one-name study is a project researching a specific surname, as opposed to a particular pedigree (ancestors of one person) or descendancy (descendants of one person or couple). Some people who research a specific surname may restrict their research geographically and chronologically, perhaps to one country and time period, while others may collect all occurrences world-wide for all time. A one-name study is not limited to persons who are related biologically. Studies may have a number of family trees which have no link with each other. Findings from a one-name study are useful to genealogists. Onomasticians, who study