Second-in-command (2i/c or 2IC) is a title denoting that the holder of the title is the second-highest authority within a certain organisation.

Usage

In the

British Army The British Army is the principal Army, land warfare force of the United Kingdom. the British Army comprises 73,847 regular full-time personnel, 4,127 Brigade of Gurkhas, Gurkhas, 25,742 Army Reserve (United Kingdom), volunteer reserve perso ...

Royal Marines The Royal Marines provide the United Kingdom's amphibious warfare, amphibious special operations capable commando force, one of the :Fighting Arms of the Royal Navy, five fighting arms of the Royal Navy, a Company (military unit), company str ...

, the second-in-command is the deputy commander of a unit, from

battalion A battalion is a military unit, typically consisting of up to one thousand soldiers. A battalion is commanded by a lieutenant colonel and subdivided into several Company (military unit), companies, each typically commanded by a Major (rank), ...

regiment A regiment is a military unit. Its role and size varies markedly, depending on the country, military service, service, or administrative corps, specialisation. In Middle Ages, Medieval Europe, the term "regiment" denoted any large body of l ...

downwards. This terminology is also used in many other Commonwealth armies and other nations. The equivalent appointment in the

United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...

is the

executive officer An executive officer is a person who is principally responsible for leading all or part of an organization, although the exact nature of the role varies depending on the organization. In many militaries and police forces, an executive officer ...

. The second-in-command of a battalion or regiment is usually a major. The second-in-command of a

company A company, abbreviated as co., is a Legal personality, legal entity representing an association of legal people, whether Natural person, natural, Juridical person, juridical or a mixture of both, with a specific objective. Company members ...

, squadron, or artillery battery (in which they are called the battery captain) is usually a captain (although

infantry Infantry, or infantryman are a type of soldier who specialize in ground combat, typically fighting dismounted. Historically the term was used to describe foot soldiers, i.e. those who march and fight on foot. In modern usage, the term broadl ...

company second-in-commands were usually

lieutenant A lieutenant ( , ; abbreviated Lt., Lt, LT, Lieut and similar) is a Junior officer, junior commissioned officer rank in the armed forces of many nations, as well as fire services, emergency medical services, Security agency, security services ...

s until after the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

), the second-in-command of a

platoon A platoon is a Military organization, military unit typically composed of two to four squads, Section (military unit), sections, or patrols. Platoon organization varies depending on the country and the Military branch, branch, but a platoon can ...

or troop is the platoon or troop

sergeant Sergeant (Sgt) is a Military rank, rank in use by the armed forces of many countries. It is also a police rank in some police services. The alternative spelling, ''serjeant'', is used in The Rifles and in other units that draw their heritage f ...

, and the second-in-command of a section is usually a

lance corporal Lance corporal is a military rank, used by many English-speaking armed forces worldwide, and also by some police forces and other uniformed organisations. It is below the rank of corporal. Etymology The presumed origin of the rank of lance corp ...

. In the

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

and Commonwealth navies, the second-in-command of a vessel, regardless of rank, is known as the

first lieutenant First lieutenant is a commissioned officer military rank in many armed forces; in some forces, it is an appointment. The rank of lieutenant has different meanings in different military formations, but in most forces it is sub-divided into a se ...

or executive officer.

Other uses

In common usage, the term refers to a deputy. Its basic meaning is "someone who relieves a commander".

References

{{reflist Military ranks