 Colonel Eustace James Anthony Balfour ( 8 June 1854 – 14 February 1911 ) was a London @-@ based Scottish architect . The brother of one British Prime Minister and nephew of another , his career was built on family connections . His mother was the daughter of a Marquess , and his wife Frances , a noted suffragist , was the daughter of a Duke . Frances 's sister in @-@ law was Princess Louise , daughter of the reigning Queen Victoria . 
