"In the King's service of course"
Painting depicting the recapture of H.M.S Hermione by the Royal Navy (1815)
Public DomainPainting depicting the recapture of H.M.S Hermione by the Royal Navy (1815) - Credit: John Augustus Atkinson

 The phrase 'in the King's service' is usually used to describe military action carried out on behalf of the country (and therefore the reigning (male) sovereign).