A Roman cohort was a tactical unit usually consisting of only one type of soldier in the Roman army, and was created following the Marian reform. Later, even before the principate, this term took on a broader meaning and defined a group.
Legion cohorts
A Roman legion has 10 cohorts numbered from I to X. A cohort (in Latin:Cohors) is made up of 3 handles, each handle being made up of 2 centuries. Cohort I, on the other hand, is made up of 5 double centuries.
During the Republic, the cohorts were organized into three lines named hastati, principles, triarii which were divided into 120, 120 and 60 men respectively. The three lines of soldier were divided by experience and warrior skill, the youngest warriors in the front line who when the rank gives way, gives way to the most efficient rank, the Principles. In turn, the Principles could yield if necessary.
The velites, light infantry, armed with javelins or slings, were in front of the ranks and launched projectiles at the enemy. When enemies made contact, they retreated.
With the reforms of Marius, the cohort replaces the maniple as a tactical unit. All soldiers are equipped and trained in the same way. Also the centuria went from 100 men to 80. Thus the typical cohort went to 6 x 80 =480 men and 5 x 160 =800 men for the 1st cohort.
Hierarchy
The military cohort is commanded by a centurion, Pilus Prior. There are 6 centurions per cohort. The highest ranking centurion commands Cohort I, his title is Primus Pilus or primipile centurion. Here are the titles of the six centurions, typical cohorts II through X:
in hierarchical order in order of battle
* Centuria I:Pilus Prior
* Century II:Princeps Prior
* Centuria III:Hastatus Prior
* Centurie IV:Pilus Posterior
* Century V:Princeps Posterior
* Century VI:Hastatus Posterior
* Centurie III:Hastatus Prior (Hastati)
* Century VI:Hastatus Posterior (Hastati)
* Centurie II:Princeps Prior (Principles)
* Century V:Princeps Posterior (Principles)
* Centuria I:Pilus Prior (Triarii)
* Centurie IV:Pilus Posterior (Triarii)
Civil Security Cohorts
* Cohors urbana security of days... Organized on the type of the praetorian cohorts, but without cavalry contingent, the urban cohorts comprised 1,000 men per cohort, even 1,500 before Vitellius.
* Cohors vigilum firefighters, night security... This body is divided in Rome into 560 men commanded by a tribune. Each cohort is divided into centuria of 70 to 80 men and commanded by a centurion princeps and six simple centurions.
Other cohorts
In the auxiliary cohorts, there are 6 to 10 centuries. The cavalry wings (Cohors alaria) comprised 500 (for the cohors quingenaria) or 1000 (for the cohors milliaria) horsemen and were divided into 16 or 24 turmas, each of which was commanded by a decurion.
Other types of cohorts:
* Cohors classica:Roman Navy
* Cohors equitata:Infantry troop supported by a cavalry troop.
* Cohors Germanorum
* Cohors milliaria
* Cohors palatina
* Cohors peditata:Infantry Troop
* Cohors praetoria
o Cohors togata:Member of the Praetorian Guard and the only soldier to have the right to take up arms in Rome.
* Cohors quigenaria
* Cohors speculatorum
* Cohors torquata
* Cohors tumultuaria:Non-standard auxiliary troops