General Officer

The various grades of general officer are at the top of the rank structure, but in some countries the highest general officers are titled Field Marshal or Marshal.

The rank of General came about as a "Captain-General", the captain of an army in general, i.e. the whole army. The rank of Captain-General began appearing around the time of the organization of professional armies in the 17th century. In most countries "Captain-General" contracted to just "General". General was also added as an adjective to existing names of ranks, yielding Colonel General, Lieutenant General and Sergeant Major General. Other terms then came about such as lieutenant-general, i.e. lieutenant (assistant leader) over the army in general. All officers who commanded more than a single regiment (the most significant level of unit) came to be known as a "general officer". General officer ranks often include the word "general", e.g. major-general, but not always, e.g. brigadier.

While historically an army rank, General is also used in many air forces, although many air forces are based on the British Royal Air Force system (e.g. UK, India, Pakistan, New Zealand, Nigeria etc.) and use Air Marshal instead, with Air Officer being the generic title for general officers in these air forces. In most navies of the world, the equivalent rank is Admiral and the generic term is Flag Officer; however a noteworthy historical exception was the Cromwellian naval rank General at sea. In recent years in the American service there is a tendency to use "Flag Officer" and "Flag Rank" to refer to generals and admirals of the services collectively.