Legio, legionis (f., third declension) is the Latin word for "legion," the main unit of the Roman army, made up of thousands of soldiers organized into cohorts and centuries. It is core military vocabulary for reading Caesar's De Bello Gallico on the AP Latin exam.
Legio, legionis, f. means "legion," the basic large-scale unit of the Roman army. A legion held several thousand soldiers (milites), broken down into cohorts and centuries, with centurions commanding at the ground level. When Caesar says he marched with two legions, he means roughly 10,000 men.
The word itself tells a story. It comes from legere, "to gather" or "to choose," so a legio is literally "the levy," the men picked for service. That word-formation pattern is exactly the kind of clue the CED wants you to use for unfamiliar vocabulary (AP Latin 1.23.B). Grammatically, legio is a third-declension feminine noun, so you have to track its case to know its job in the sentence. Legio is the subject, legionem the direct object, legioni an indirect object, and legione shows up after prepositions like cum or in ablative constructions.
Caesar's De Bello Gallico is half of the AP Latin syllabus, and legions are what Caesar writes about. You cannot get through a chapter of Caesar without hitting legio or its relatives, which makes it a textbook case for the Unit 1 vocabulary objectives. AP Latin 1.23.A expects you to know required vocabulary cold, and 1.23.C expects you to explain how case, number, and gender shape a word's function in context. Misreading legionem as a subject instead of an object wrecks a translation, and translation accuracy is scored phrase by phrase. The same military vocabulary world carries over to topic 1.23, the Vergil Aeneid war scenes, where battle language is everywhere even though the armies are mythological.
Keep studying AP Latin Unit 1
castra (Unit 1)
The legion and the camp travel together in Caesar's narrative. The legio is the people; the castra is the place they fortify and sleep. Caesar constantly moves legions out of camp (ex castris) or back into it, so these two words anchor most of his military sentences.
centurion (Unit 1)
Centurions are the officers inside a legion, each commanding a century of about 80-100 men. When Caesar praises individual bravery, he usually names a centurion, so knowing how the legion is built helps you follow who outranks whom in a passage.
Turnus (Unit 1, topic 1.23)
Vergil's war scenes in the Aeneid run on the same battle vocabulary you learn from Caesar, just aimed at epic combat. Turnus leads Italian forces against Aeneas, and recognizing military terms like legio makes those war-scene passages much faster to read.
On the multiple-choice section, legio shows up in sight-reading passages where you identify its case and function, exactly what AP Latin 1.23.C tests. On the free-response side, the literal translation SAQs from Caesar are where this word earns its keep. The 2017 translation question, where a shorthanded Caesar comes to the rescue, sits squarely in this military world, and the 2022 SAQ about the British chieftains hinges on phrases like paucitatem militum, the small number of soldiers. Scorers grade these translations segment by segment, so rendering legio with the right case function (subject vs. object vs. ablative of accompaniment) is worth real points. You may also be asked to explain a passage in context, where knowing what a legion actually is helps you describe Caesar's strategy accurately.
Legio is the unit of soldiers; castra is the fortified camp where they live. Students mix them up because both are everywhere in Caesar and both are 'army words.' A quick grammar check helps too. Castra is neuter plural in form even when it means one camp, while legio is a regular third-declension feminine noun that declines normally (legio, legionem, legionis...).
Legio, legionis is a third-declension feminine noun meaning "legion," the main Roman army unit of several thousand soldiers.
The word comes from legere, "to choose," so a legion is literally "the levy" of men selected for service, a word-formation clue the CED explicitly rewards.
Case endings tell you what the legion is doing in the sentence, so legio acts, legionem is acted upon, and legione often follows a preposition.
A legion is divided into cohorts and centuries, with centurions as the officers Caesar most often names for individual bravery.
Caesar translation SAQs are scored phrase by phrase, so correctly handling military vocabulary like legio directly affects your score.
The same battle vocabulary carries from Caesar's prose into Vergil's war scenes in the Aeneid, so learning it once pays off twice.
Legio (genitive legionis, feminine) means "legion," the primary unit of the Roman army, several thousand soldiers strong. It derives from legere, "to choose," because legionaries were levied or selected for service.
Roughly 4,000 to 6,000 men in Caesar's era, organized into cohorts and centuries. For AP Latin you don't need an exact headcount, but you should know a legion is a large multi-thousand-man unit led at ground level by centurions.
No. Legio is the body of soldiers, while castra is the fortified camp they build and occupy. Castra is also grammatically odd (neuter plural in form even for one camp), while legio declines as a normal third-declension noun.
Yes. AP Latin 1.23.C requires you to explain how case shows a noun's function, and translation questions are scored on whether you render those functions correctly. Knowing that legionem is accusative and legione is ablative can be the difference between a correct and incorrect translation segment.
It's most frequent in Caesar's De Bello Gallico, but Vergil's war scenes in the Aeneid use the same military vocabulary for the fighting between Aeneas's Trojans and Turnus's Italian forces. Learning it for Caesar makes the epic battle passages easier to sight-read.