Centenaria (singular centenarium) were fortified farms in northern Africa – Tripolitania (northwestern part of Libya; near the coast). So far, we have found the remains of over 2,000 such objects, including Gheriat esh-Shergia, Qasr Banat or Suq al-Awty, which were the so-called Limes Tripolitanus.
These types of buildings arose mainly from the need for independent protection of property against nomadic tribes (Nomads) living in deserts, which moved efficiently thanks to dromedaries. Due to the fact that the lands were fertile, the inhabitants mainly cultivated grain, dates, figs, olives and vegetables. Goats, dromedaries and cows were also bred.
Who were the people who settled in these lands and cultivated it? They were usually veterans who were given land after their service or Nomads who chose a sedentary lifestyle. In the 3rd century CE Tripolitania was ethnically diverse, what however, did not interfere with cooperation.
All the mentioned farms were built on a square plan and had watchtowers that enabled communication with each other. In this way, it was easy to warn surrounding farms of danger and organize defense together. Farm owners were the beginning of later infantry troops limitanei,, which were to take their first attack at the borders and persevere until strontium support of the more volatile troops. This type of organization already existed fully during the reign of Constantine I (ruled in 306-337 CE).