Centuriation (according to lat. centum = hundred), known as such in Roman cadastral land division procedures, was based on the concept of the centuria, an area roughly measuring 700 meters per side and comprising a hundred smaller parts.
Centuriation served as a means for the Romans to systematically divide land into uniform parcels allocated to new settlers in colonies or newly established cities within conquered territories. To ensure equitable distribution of land among colonists, the entire agricultural area of the colony underwent measurement and division into regular plots. Through surveying, two principal axes were established perpendicular to each other, originating from a central point known as the umbilicus, using specialized surveying instruments. These axes formed the basis for the layout of the entire grid across the designated area. Those running east-west were termed decumanus, while those in the north-south direction were referred to as cardo. The smallest unit of a plot measured 35 by 35 meters (known as an “actus quadratus”), with the most common size being 70 by 70 meters, or approximately 0.5 hectares.
Traces of centuriation persist today and can be identified on cadastral and topographic maps as well as aerial photographs. Notably, the regions of the Istrian colonies, such as Pola and Parentium, exhibit clear evidence of this grid pattern, with remnants of orthogonal axes still visible around Pula, extending towards Fažana, Vodnjan, and Bale.
