The following table was compiled by John Reid, and can be found on his Canada’s Anglo-Celtic Connections blog. The table includes the titles of various British Military databases as found on Ancestry, FamilySearch (FS), Findmypast (FMP) and The (UK) National Archives (TNA), and is reproduced here with his permission.

Database Company Service
British Royal Navy & Royal Marines Service and Pension Records Browse, 1704-1919 FMP Navy
British Royal Navy & Royal Marines Service and Pension Records, 1704-1919 FMP Navy
British Army, List Of Half-Pay Officers 1714 FMP Army
UK, Royal Hospital Chelsea Pensioner Admissions and Discharges, 1715-1925 Ancestry Army
British Army, Royal Artillery Officers 1716-1899 FMP Army
British Royal Navy, Ships’ Musters FMP Navy
British India Office Army & Navy Pensions FMP Army & Navy
Royal Navy officers’ service records 1756-1931 TNA Navy
Web: UK, Royal Naval Officers’ Service Records Index, 1756-1931 Ancestry Navy
UK, Royal Hospital Chelsea Pensioner Soldier Service Records, 1760-1920 Ancestry Army
UK, Chelsea Pensioners’ Service Records, 1760-1913 FS Army
UK, Royal Hospital Chelsea: Discharge Documents of Pensioners 1760-1887 FS Army
Great Britain, War Office Registers, 1772-1935 FS Army
Cornwall, England, Militia and Sea Fencibles Index, 1780 – 1831 Ancestry All
British Army Pensioners – Royal Hospital Kilmainham, Ireland, 1783-1822 FMP Army
Army List 1787 FMP Army
British Mariners, Trinity House Calendars 1787-1854 FMP Marines
British Royal Navy Allotment Declarations 1795-1852 FMP Navy
Army List 1798 FMP Army
Household Cavalry soldiers’ service records 1799-1920 TNA Army
British Army Officer Promotions 1800-1815 FMP Army
UK, British Army Lists, 1882-1962 Ancestry Army
British Army Schoolchildren and Schoolmasters 1803-1932 FMP Army
London, Watermen In Royal Navy, 1803-1809 FMP Navy
UK, Militia Service Records, 1806-1915 FS Army
UK, Naval and Military Courts Martial Registers, 1806-1930 Ancestry Navy
British Army Muster Rolls, 84th Foot 1808-1818 FMP Army
Peninsular War, British Army Officers, 1808-1814 FMP Army
UK, Military Deserters, 1812-1927 Ancestry Army
UK, British Army Muster Books and Pay Lists, 1812-1817 Ancestry Army
British Army, War Of 1812 Casualties FMP Army
British Royal Marines, Marriage Registers 1813-1920 FMP Marines
Army Deserters 1828-1840 FMP Army
British Royal Navy Personnel 1831 FMP Navy
UK, Merchant Navy Seamen Records, 1835-1941 FS Navy
Harts Army List 1840 FMP Army
Royal Navy officers’ service record cards and files c.1840-c.1920 TNA Navy
British Army, Worldwide Index 1841 FMP Army
Royal Marines’ service records 1842-1925 TNA Marines
UK, Royal Navy Registers of Seamen’s Services, 1848-1939 Ancestry Navy
British Army, Royal Artillery Officer Deaths 1850-2011 FMP Army
British Army, Worldwide Index 1851 FMP Army
England & Wales Merchant Navy Crew Lists 1861-1913 FMP Navy
Royal Navy ratings’ service records 1853-1923 TNA Navy
Web: UK, Royal Naval Seamen Index, 1853 -1872 Ancestry Navy
British Army Discharges, 60th Foot 1854-1880 FMP Army
East India Register & Army List 1855 FMP Army
Victoria Cross registers 1856-1944 TNA Army
Royal Naval Reserve service records 1860-1955 TNA Navy
British Army, Worldwide Index 1861 FMP Army
British Army, Worldwide Index 1871 FMP Army
Indian Army & Civil Service List 1873 FMP Army
Army List August 1878 FMP Army
British Army Muster Rolls, 60th Foot 1879-1882 FMP Army
British Army, Northumberland Fusiliers 1881-1920 FMP Army
Harts Army List 1888 FMP Army
Royal Marines 1899-1919 FMP Marines
British Royal Navy Seamen 1899-1924 FMP Navy
Royal Navy Officers 1899-1919 FMP Navy
UK, Army Registers of Soldiers’ Effects, 1901-1929 Ancestry Army
Volunteer Reserve service records 1903-1922 TNA Navy
British Army Service Records Image Browse FMP Army
Royal Naval Air Service officers’ service records 1906-1918 TNA Navy
British Army, Honourable Artillery Company FMP Army
British Royal Air Force, Airmen’s Service Records 1912-1939 FMP Air Force
British Royal Air Force, Officers’ Service Records 1912-1920 FMP Air Force
UK, Royal Air Force Muster Roll, 1918 Ancestry Air Force
UK, British Jewry Roll of Honour, 1914-1918 Ancestry All
Bexley, Kent, England, WWI Registration Cards, 1914-1919 Ancestry All
Prisoner of war interview reports 1914-1918 TNA Army
British Army medal index cards 1914-1920 TNA Army
British Army nurses’ service records 1914-1918 TNA Army
British Army war diaries 1914-1922 TNA Army
Soldiers’ service records TNA Army
Soldiers’ pension records TNA Army
UK, British Army Recipients of the Military Medal, 1914-1920 Ancestry Army
Surrey, England, Regimental Rolls, 1914-1947 Ancestry Army
UK, WWI War Diaries (Gallipoli and Dardanelles), 1914-1916 Ancestry Army
UK, WWI War Diaries (France, Belgium and Germany), 1914-1920 Ancestry Army
UK, WWI Service Medal and Award Rolls, 1914-1920 Ancestry Army
British Army Service Records FMP Army
British Army, Bond Of Sacrifice: Officers Died In The Great War 1914-1916 FMP Army
British Army, De Ruvigny’s Roll Of Honour 1914-1918 FMP Army
British Army, Deserters and Absentees In Police Gazette 1914-1919 FMP Army
British Army, Lloyds Of London Memorial Roll 1914-1919 FMP Army
British Army, Royal Artillery War Commemoration Book, 1914-1918 FMP Army
UK, World War I Service Records, 1914-1920 FS Army
Merchant seamen’s campaign medal records 1914-1918 TNA Merchant Navy
UK, Shipping and Seamen WWI and WWII Rolls of Honour, 1914-1945 Ancestry Merchant Navy
Royal Naval Division service records 1914-1919 TNA Navy
British Royal Navy & Royal Marines, Battle Of Jutland 1916 Servicemen FMP Navy
Women’s Army Auxiliary Corps service records 1917-1920 TNA Army
British Army, Women’s Army Auxiliary Corps 1917-1920 FMP Army
UK, World War I Women’s Army Auxiliary Corps Records, 1917-1920 FS Army
Women’s Royal Naval service records 1917-1919 TNA Navy
Royal Air Force officers’ service records 1918-1919 TNA Air Force
Women’s Royal Air Force service records 1918-1920 TNA Air Force
UK, Royal Air Force Airmen Records, 1918-1940 Ancestry Air Force
Web: UK, Women’s Royal Air Force Index, 1918-1920 Ancestry Air Force
British Women’s Royal Air Force Service Records 1918-1920 FMP Air Force
Royal Air Force Muster Roll 1918 FMPt Air Force
British Army, Plovdiv Military Cemetery Burials FMP Army
UK, Military Discharge Indexes, 1920-1971 Ancestry Army
UK, Electrical Engineer WWI and WWII Rolls of Honour, 1924, 1949 Ancestry All
Army Roll Of Honour 1939-1945 FMP Army
British Army Casualty Lists 1939-1945 FMP Army
British Army Casualty Lists 1939-1945 Image Browse FMP Army
British Army, Royal Artillery, 80th Field Regiment, WW2 FMP Army
UK, WWII Civil Defence Gallantry Awards, 1940-1949 Ancestry Civilian