“ In 16th and 17th century armies the title serjeant is found amongst the highest ranks of an army. With a partial return to the old meaning it signifies, in all its forms, an expert professional soldier, the serjeant of a company, the serjeant-major of a regiment and the serjeant-major-general of the army (these last the originals of the modern ranks, major and major-general) being charged with all duties pertaining to the arraying, camping and drill of their units.
In modern armies the word serjeant is used of a non-commissioned officer ranking between corporal and serjeant-major. ”

“ A “lance-serjeant” is a corporal holding the appointment and performing the duties, but not having the rank of serjeant. The serjeant-major in the British service is a “warrant-officer,” although in the cavalry and artillery the ranks of “troop,” “squadron” or “battery serjeant-major” are non-commissioned and correspond to the “colour-serjeant” of infantry. This last officer is the senior non-commissioned officer of a company, and has, besides his duties in the colour-party, the pay and accounting work of his unit. ”

“ Serjeants-at-Arms.—In the British royal household there are eight serjeants-at-arms, whose duties are ceremonial; they have to be in attendance only at drawing-rooms, levees, state balls and state concerts. ”