Military service by British royalty

Many members of the British Royal Family have seen service in British or other Commonwealth armed forces, others hold honorary ranks or positions. This is a list detailing formal military service by members of the British royal family.
The honorary ranks and titles are included in a separate column. The "rank whilst active" column dictates the rank worn and held whilst the Royal was serving with the armed forces and the "current rank worn" column denotes any rank worn currently (notably honorary rank, promotions). Members of the royal family receive regular promotions even after their active service has ended.
Key.
A number of abbreviations, acronyms and initialisms are used, to save space:
List.
Notes
N.B. Upon leaving active service, royal members are generally promoted to the rank they would have received, if they had stayed in the Armed Services.
Military service of English monarchs.
A few English monarchs came to the throne from other countries and served in the armies of their home country. A few served in other armies during their exile.