The 1st cohort of elite soldiers had 5 double sized centuries. In the imperial period, the full complement was 5,500 men split into 10 cohorts of 480 men each. of 80 men. The three lines were 75 m (250 feet) apart, and from front to rear one maniple of each line formed a cohort of 420 men; this was the Roman equivalent of a battalion.
It had a complement of 4,200 legionaries in the republican period of Rome.
The size of a typical legion varied during the history of ancient Rome. Forts varied in size with the smallest measuring under a single hectare while the larger ones could be over 50 hectares in area. More often, a legion consisted of 4000 to 4800 combat ready troops. A Roman legion had 10 cohorts. Cohorts 2 to 10 had 6 centuries of 80 men.

"The Size and Organization of the Roman Imperial Legion," by Jonathan Roth; Historia: Zeitschrift für Alte Geschichte, Vol. What truly made the Roman Legions the best fighting force throughout the ancient world, were the structured nature of the army, and the formations they used in battle. This makes a total of 59 centuries and 5,120 infantrymen. The historians admit of exceptions with legion size going as low as 3000 and as high as 6000, with cavalry ranging from 200-400. Each cohort occupied a space 36.6 meters wide by 54.9 meters deep (120 feet wide and 180 feet deep). The auxiliaries are also explained, but simplified and in short. A neat video visualizing the core concept of how a Roman army was structured, from the grunt legionary all the way up to the legatus legionis.

This is a list of Roman legions, including key facts about each legion, primarily focusing on Principate (early Empire, 27 BC - 284 AD) legions, for which there exists substantial literary, epigraphic and archaeological evidence.. Until the 1st century BC, legions were temporary citizen levies, raised for specific campaigns and disbanded after them. In fact, the last certain piece of evidence relating to the existence of the Legion from anywhere in the Roman Empire comes from York where an … Sometimes the number one cohort was twice the size of the others.

Let’s assume you are talking about an early imperial legion, not a republican one pre Marius’ reform or a later roman army. The centurion was the commander of a centuria, which was the smallest unit of a Roman legion.A legion was nominally composed of 6,000 soldiers, and each legion was divided up into 10 cohorts, with each cohort containing 6 centuria. Legio (Legion) - (10 Cohorts = 5,000 men) Until the middle of the first century, 10 cohorts (about 5,000 men) made up a Roman Legion. In the early Empire, the number of legions was initially reduced to 28 (minus 3 annihilated and not reestablished after the Teutoburger Wald battle), with the size of the actual legion still around 5000 but the size of the attached auxiliaries increased to roughly the same size, so nominal a legion commander had about 10000 man at his disposal. Roman forts were typically rectangular with rounded corners & protected by palisades, ramparts, towers, & ditches.

An example of the larger type fort is at Vetera and Oberaden in Germany, which housed two legions each. This is a list of Roman legions, including key facts about each legion, primarily focusing on Principate (early Empire, 27 BC - 284 AD) legions, for which there exists substantial literary, epigraphic and archaeological evidence.