Thus, his cousin, Prince Louis of Battenberg, became Louis Mountbatten, 1st Marquess of Milford Haven, while his brother-in-law, the Duke of Teck, became Adolphus Cambridge, 1st Marquess of Cambridge. Others, such as Princess Marie Louise of Schleswig-Holstein and Princess Helena Victoria of Schleswig-Holstein, simply stopped using their territorial designations. The system for titling members of the royal family was also simplified.[33] Relatives of the British royal family who fought on the German side were simply cut off; their British peerages were suspended by a 1919 Order in Council under the provisions of the Titles Deprivation Act 1917.[34]