Earlier today I randomly stumbled on the Sandhurst Collection website, where you can download entries from the Royal Military Academy‘s registers. The database is searchable online, and a scan of each entry can be downloaded for a small fee.
The entries do not contain anything too juicy, but all the same they tell you when an officer cadet was there, their basic personal information, and useful information such as their father’s occupation. Although it doesn’t seem like much, used alongside registration records, census returns and subsequent Army lists it helps you pin down the early years of an officer’s career.
The entry’s wont include wartime emergency commission officers, sadly, as Sandhurst closed in 1939 for the duration of the war. Many pre-war and post-war officers can be found, however, including Winston Churchill, Bernard Montgomery, Alan Brooke, Frederick Browning and Roy Urquhart. Closer to home I have also found the entry for Major Robert Easton MBE DSO, from Portsmouth.