Eustace Balfour of James Gascoyne-Cecil, 2nd Marquess of Salisbury. His paternal grandfather James Balfour was a nabob who had made the family's fortune as a contractor supplying the Royal Navy in India and became a Tory Member of Parliament (MP), while his mother's father was a Conservative cabinet minister in the 1850s. Her brother, Robert Gascoyne-Cecil, 3rd Lord Salisbury, was three times Prime Minister before being succeeded in 1902 by Eustace's elder brother Arthur Balfour. Eustace Balfour was educated at Harrow and at Trinity College, Cambridge, where he graduated in 1873. He then studied architecture under Basil Champneys, the designer of Newnham
First Lord of the Treasury residence is also used by other senior members of government. Much of this list overlaps with the list of Prime Ministers of the United Kingdom, but there are some notable differences, principally concerning the Marquess of Salisbury, who was Prime Minister but not First Lord in 1885–86, 1887–92 and 1895–1902. Those First Lords who were simultaneously Prime Minister are indicated in bold; those First Lords who were considered Prime Minister only during part of their term are indicated in bold italic. Thereafter the posts of First Lord of the Treasury and Prime Minister have continually been held by the same