"England and Wales Marriage Registration Index, 1837-2005," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:26FC-YK3 : 13 December 2014), George L V H S Battenberg and null, 1916; from “England & Wales Marriages, 1837-2005,” database, findmypast (http://www.findmypast.com : 2012); citing 1916, quarter 4, vol. 1A, p. 1194A, St. Martin, London, England, General Register Office, Southport, England.
WIkipedia George Mountbatten, 2nd Marquess of Milford Haven
Capt George Louis Victor Henry Serge Mountbatten on Find A Grave: Memorial #61929192 retrieved 29 sep 2016
It may be possible to confirm family relationships with George by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree: