For the film, see Second in Command

Second in Command

Second in Command is a 2006 action film directed by Simon Fellows, starring Jean-Claude Van Damme. It was released direct-to-video in the United States, Belgium, and Germany on May 2, 2006. It has been rated R by the MPAA for violence and some language. The film was made in Bucharest, Romania.-Plot...

.

The Second-in-Command (2i/c or 2IC) is the deputy commander of any British Army

British Army

The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...

 or Royal Marines

Royal Marines

The Corps of Her Majesty's Royal Marines, commonly just referred to as the Royal Marines , are the marine corps and amphibious infantry of the United Kingdom and, along with the Royal Navy and Royal Fleet Auxiliary, form the Naval Service...

 unit, from battalion

Battalion

A battalion is a military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a Lieutenant Colonel or a Colonel...

 or regiment

Regiment

A regiment is a major tactical military unit, composed of variable numbers of batteries, squadrons or battalions, commanded by a colonel or lieutenant colonel...

 downwards. He or she is thus the equivalent of an Executive Officer

Executive officer

An executive officer is generally a person responsible for running an organization, although the exact nature of the role varies depending on the organization.-Administrative law:...

 in the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

. This terminology is also used in many other Commonwealth

Commonwealth of Nations

The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...

 armies.

The Second-in-Command of a battalion is usually a Major

Major

Major is a rank of commissioned officer, with corresponding ranks existing in almost every military in the world.When used unhyphenated, in conjunction with no other indicator of rank, the term refers to the rank just senior to that of an Army captain and just below the rank of lieutenant colonel. ...

 and the second-in-command of a regiment is a Lieutenant Colonel

Lieutenant colonel

Lieutenant colonel is a rank of commissioned officer in the armies and most marine forces and some air forces of the world, typically ranking above a major and below a colonel. The rank of lieutenant colonel is often shortened to simply "colonel" in conversation and in unofficial correspondence...

. The Second-in-Command of a company

Company (military unit)

A company is a military unit, typically consisting of 80–225 soldiers and usually commanded by a Captain, Major or Commandant. Most companies are formed of three to five platoons although the exact number may vary by country, unit type, and structure...

, squadron or artillery battery

Artillery battery

In military organizations, an artillery battery is a unit of guns, mortars, rockets or missiles so grouped in order to facilitate better battlefield communication and command and control, as well as to provide dispersion for its constituent gunnery crews and their systems...

 (in which he or she is called the Battery Captain) is usually a Captain (although infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

 company Second-in-Commands were usually Lieutenant

Lieutenant

A lieutenant is a junior commissioned officer in many nations' armed forces. Typically, the rank of lieutenant in naval usage, while still a junior officer rank, is senior to the army rank...

s until after the Second World War), the Second-in-Command of a platoon

Platoon

A platoon is a military unit typically composed of two to four sections or squads and containing 16 to 50 soldiers. Platoons are organized into a company, which typically consists of three, four or five platoons. A platoon is typically the smallest military unit led by a commissioned officer—the...

 or troop

Troop

A troop is a military unit, originally a small force of cavalry, subordinate to a squadron and headed by the troop leader. In many armies a troop is the equivalent unit to the infantry section or platoon...

 is the Platoon or Troop Sergeant

Sergeant

Sergeant is a rank used in some form by most militaries, police forces, and other uniformed organizations around the world. Its origins are the Latin serviens, "one who serves", through the French term Sergent....

, and the Second-in-Command of a section

Section (military unit)

A section is a small military unit in some armies. In many armies, it is a squad of seven to twelve soldiers. However in France and armies based on the French model, it is the sub-division of a company .-Australian Army:...

 is usually a Lance Corporal

Lance Corporal

Lance corporal is a military rank, used by many armed forces worldwide, and also by some police forces and other uniformed organizations. It is below the rank of corporal, and is typically the lowest non-commissioned officer, usually equivalent to the NATO Rank Grade OR-3.- Etymology :The presumed...

.

In the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

, the second-in-command of a vessel is known as the First Lieutenant

First Lieutenant

First lieutenant is a military rank and, in some forces, an appointment.The rank of lieutenant has different meanings in different military formations , but the majority of cases it is common for it to be sub-divided into a senior and junior rank...

 or Executive Officer.

Other meanings/uses

Less formally, "second-in-command" is a term used, usually unofficially and sometimes jocularly, for any deputy. Its basic meaning is "someone who relieves a commander". When the first-in-command is absent, the second-in-command will temporarily assume the duties thereof.