Major is a military rank the use of which varies according to country. Depending on the country, the rank derives either from "Captain-Major", a rank of senior captain, or "Sergeant-Major" a rank of senior sergeant.

In most countries Major derives from Captain-Major and denotes a mid-level command status officer (immediately superior to the rank of Captain and immediately subordinate to the rank of Lieutenant Colonel). Where major derives from sergeant major, notably in France, major is a senior sub-officer rank.

Early history

In considering terms of rank it is important to understand that the early evolution of the terms often was outside of English, and that the term always has been of essentially international distribution. In general European usage, the rank of Major originates from Romance comparative adjectives with the sense of Latin maior (also spelled major), meaning 'senior' and 'greater'. Historically all Majors, Sergeants Major, and Major Generals (to use English forms) derive from the rank, or rather the office of Sergeant Major. The Sergeant Major was the senior sergeant responsible for marshalling a battalion of pike. He was presumably the senior Company Sergeant from among the companies providing the pikemen, or at least a commissioned officer considered analogous to such a non-commissioned officer (sergeant). Hence, Major is an abbreviation of Sergeant Major: the (Sergeant) Major 'the senior sergeant'. This is obscured in French and English, by the later evolution of a separate, non-commissioned rank called sergent major or Sergeant Major. Similarly, the rank of Major General is truncated from original Sergeant Major General 'the sergeant major or sergeant major-like soldier with general authority over the marshalling of the whole army'. Originally, there existed a single Sergeant Major General in each major field force.

The original usage is illustrated in the first recorded(?) English (1643) attestation, as "Sergeant-Major", 'the third-in-command of a regiment'. The early German equivalent was Feld Wachtmeister, in which Field functions as major and Wachtmeister ('watch master' or 'quarter1 master') is the more commonly used term for a cavalry sergeant. Similarly we early on find Spanish Majors referred to Sargento Major.

In several European navies, the rank of Major was used in the sense or form "Pilot-Major" to denote the senior deck officer of a vessel in contrast to the Captain (or Captain General) who was typically an Army officer, with little naval knowledge, assigned to command the mission on which a vessel was embarked. The English equivalent of this usage is Master, as opposed to the Captain or Commander.

In the Spanish navy of the 16th and 17th centuries, the captain's principal seaman was the "maestre" (master) who was responsible for the maritime operation of the ship. Next in the chain of command was the "piloto" (pilot) responsible for the safe navigation of the ship. A flagship's pilot was the "piloto mayor" (chief or major pilot) who determined the course of the whole squadron.