Marriage for members in the Imperial family required an Imperial sanction, and they were only allowed to marry other members of the Imperial family or, with special Imperial sanction, members of the peerage (Articles 39 and 40 of the former Imperial House Act).
皇族の結婚は、皇族同士か特に勅許を受けた華族との間に限られ、勅許を必要とした（旧皇室典範39,40条）。