What was the origin of the roles of "lieutenant" officers?

Question

A "captain" is a commander of a basic unit, a company in the military. As such, it makes sense that he will have one or more "lieutenants," first and second lieutenants that is.

A major commands the next higher level unit, a battalion. But there's no such thing as a "lieutenant major."

A colonel commands the next higher level unit, a regiment. He is two ranks above a major, with the intervening rank being a "lieutenant" colonel.

So why isn't a "first lieutenant" (second lowest commissioned officer) a captain, while a "captain" (the third lowest commissioned officer) a lieutenant major?

A "major (two star) general" commands the next higher unit, a divison. A one star general is a "brigadier general," who used to command a brigade, when there were four regiments in a division, meaning two regiments to a brigade and two brigades to a division. But when brigades were abolished, "brigadier general" lost its original meaning. Is he now a "lieutenant" major general?

A "lieutenant" (three star) general is one level below a "full" (four star) general. And a five star general is a "general of the army." Does this mean that a five star general is an army general, a four star general is a commander of a corps (the unit between a division and an army), and a three star general is a "lieutenant" corp commander?

Was it the original intent of the Anglo American armies to have "lieutenant" and then "full" officers at each level (captain, colonel, general, etc.)? Or if the ranks "evolved" over time, what was the history of the evolution?

Answer 1

The assumption I make here is the origin of Anglo-American ranks is the origin of English ranks. Not unreasonable.

"Lieutenant" derives from the French words: "lieu" - "in place" and "tenant" - "holding", it's someone who assumes command in place of the actual commander. As you said, a captain having lieutenants makes sense and pre-dated professional armies with formalised rank structures ¹. Major, meaning "superior" or "elder" in (medieval) Latin is also a logical step. Sergeant meaning "servant", corporal meaning "head" etc. These are all great prefixes to add to ranks like Colonel and General, but are probably more prefixes than we need. Captain general is a rank we used to have but now don't, for example.

It seems reasonable to say that rank formalisation came about with the first professional army. All these ranks clearly existed before, but this is the only point where a leader of trained band couldn't just 'decide' they were a "lieutenant major". This Document, The Officer List of The New Model Army, suggest that a modern rank structure existed in the New Model Army (the parliamentarian army during the English Civil War often recognised as being the first English professional army). This army was disbanded, but the 26th January 1661 Charles II issued the Royal Warrant that created the first permanent professional Infantry Regiments, renewing this rank system and introducing the sale of Commissions

I found this blog post funny, the conclusion here is that a bunch of different and inconsistent ranks got shoved together and gaps filled by adding major or lieutenant to existing ranks, the result being madness. And that's sort of the point, ranks were developed by a mix of natural evolution and arbitary decision making in the 17th century, with these prefixed ranks filling the gaps as operationally required.

_{The historical importance and independence of Captains being perhaps why we lack lieutenant Majors. Also, If you've ever wondered why major general is below lieutenant general it's because the former is a contraction of sergeant major general, which itself was an extension of an earlier meaning of sergeant major.}

Answer 2

"Major General" was originally "Sergent Major General", and had the same responsibility on the "general-level" as a "Sergent Major" had for the regiment - ie. administering the day-to-day running of the regiment and make sure it had enough supplies and such.

As the organization grew with larger armies, Sergent Majors moved downwards and became a part of the company instead. Majors took over the administrative role for the whole regiment.

With companies, we got captains - with lieutenants as their seconds. Today a platoon is lead by lieutenant (or 2nd. lieutenant or captain) and the company is lead by a captain or a major (depending on country and tradition).

The basic unit in old armies were (what became) the regiment - lead by (what became) a colonel. Nobles had to train peasant-armies for the King, a colonel stood for the training and his second was the lieutenant colonel (in-place-of colonel).

The first "generals" lead armies "instead of" the King.

Answer 3

The ranks to command various units varied a lot more than the OP says.

For example, during the US Civil War the Union army often had major generals at four or five levels of command, commanding divisions, corps, armies, groups of two or more armies within a theater of war, and the entire US army.

The rebel forces more logically had brigadier generals commanding brigades, major generals commanding divisions, lieutenant generals commanding corps, (full) generals commanding armies, and (full) generals commanding anything larger than a field army.

In the US Civil War regiments rarely contained organizational battalions, brigades usually had more than two regiments, divisions usually had more than two brigades, a corps usually had more than two divisions, and field armies had varying numbers of corps - one Union unit was designated at various times both as a corps and as the Army of West Virginia.

At about the same time British army regiments often had two or more battalions. These battalions were so separate that they might often be stationed thousands of miles apart, and brigades were usually formed from battalions all part of different regiments.

Due to differing organizational tables, and differing degrees of filling of ranks, in different armies at different times, some companies were larger than some battalions or regiments, some battalions were larger than some regiments, some regiments were larger than some brigades, and so on.

Since units of the same type had vary different sizes in different armies, and since officers of a specific rank commanded different types of unit in different armies, the usual relationship between rank and command type has varied greatly from time to time and from army to army.

Answer 4

Here are some observations: They do NOT substitute for a history of origins.

The American system seems to have three ranks for every two unit levels. For instance, a second lieutenant is a platoon commander, and a captain is a company commander, meaning that a first lieutenant is a "floater" who can be either a "senior" second lieutenant, or an adjutant company commander. Likewise, a major commands a battalion, a colonel a regiment, and a lieutenant colonel can be a senior "major" (battalion commander) or junior to a colonel in the regimental command.

Actually, a platoon can be commanded by either a senior sergeant or a second lieutenant, and the latter should be the floater position, with a company commander called a captain just above a second lieutenant, at the level of first lieutenant. Then a "captain" should be lieutenant major, while the rank above a major is a lieutenant colonel.

Originally, this "lieutenant" structure did not apply to generals so a one star general was a brigade commander, a two star "major" general a division commander, a three star "lieutenant" general a corps commander, and a four star general a "full" general of an "army" of over 100,000 men. A five star general would be the general of the "Army" (as opposed to the navy or marines. But when divisions went from four regiments to three, thereby abolishing brigades, brigadier generals (in effect) became "floaters between regiments commanded by colonels and divisions commanded by major generals.