Interesting question. A quick inquiry of grok returned this:
It's one of the most common and understandable points of confusion in military ranks!
In the U.S. military (and most English-speaking countries following British tradition), a lieutenant general (3-star) is indeed higher than a major general (2-star), despite a regular major outranking a lieutenant.
The explanation lies in history, not modern logic. The names come from much older structures (going back to the Middle Ages and 17th-century European armies):
- The overall army commander used to be called Captain General (later shortened to simply General).
- His direct deputy/second-in-command was the Lieutenant General ("lieutenant" meaning "placeholder" or "in place of" the captain general).
- Below that came the Sergeant Major General — essentially the senior staff/general administrative officer for the whole army (combining "sergeant major" = chief of staff duties + "general" = army-wide scope). This was the third-ranking general officer.
Over time (especially by the 17th–18th centuries):
- "Captain General" → just General
- "Lieutenant General" stayed the same
- "Sergeant Major General" got shortened by dropping the "sergeant" → Major General
So major general started life as a rank below lieutenant general, and the "major" part has nothing to do with the field-grade officer rank of major (O-4) that we know today.
In short:
- The "lieutenant" in lieutenant general preserves its original meaning of "deputy to the top general."
- The "major" in major general is a leftover from "sergeant major general" — a historically junior general rank.
This quirk has survived for centuries in the U.S., British, Canadian, Australian militaries (and others), while some countries (e.g., many former Soviet states) use a more "logical" progression where lieutenant general comes in below a colonel general and above major general — but without a brigadier general rank in between.
So the American system looks backward at first glance, but it's just a case of linguistic history winning out over intuitive word order.