Confirmation, in the context of Reform Judaism, was mentioned officially for the first time in an ordinance issued by the Jewish consistory of the kingdom of Westphalia at Cassel in 1810. There it was made the duty of the rabbi "to prepare the young for confirmation, and personally to conduct the ceremony." At first only boys were confirmed, on the Sabbath ("Shabbat") that they celebrated becoming Bar Mitzvah; the ceremony was performed at the home or in the schoolroom. In Berlin, Jewish girls were confirmed for the first time in 1817, in Hamburg in 1818.