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.
Surname had chosen as the family name, when this option was available for women. "Losonci Rose and Rose v. Switzerland" challenged a prohibition on foreign men married to Swiss women keeping their surname if this option was provided in their national law, an option available to women. "Ünal Tekeli v. Turkey" challenged prohibitions on women using their surname as the family name, an option only available to men. The Court found all these laws to be in violation of the Convention. Only a fraction of surnames in English-speaking countries around the world come from Britain. English speakers' surnames come from all