Centuriation

The development of the geometric and operational characteristics that were to become standard came with the founding of the Roman colonies in the Po valley, starting with Ariminum (Rimini) in 268 BCE.

[4] The agrarian law introduced by Tiberius Gracchus in 133 BCE, which included the privatisation of the ager publicus, gave a great impetus to land division through centuriation.

He then took up his position there and, looking towards the west, defined the territory with the following names: He then traced the grid using an instrument known as a groma, tracing two road axes perpendicular to each other: It has been suggested that the Roman centuriation system inspired Thomas Jefferson's proposal to create a grid of townships for survey purposes, which ultimately led to the United States Public Land Survey System.

[9] This is because, for practical reasons, the orientation of the axes did not always coincide with the four cardinal points and followed instead the orographic features of the area, also taking into account the slope of the land and the flow of rainwater along the drainage channels that were traced (centuriation of Florentia (Florence).

[10] Contemporary Roman sources as well as modern archeological results suggest that centuria varied in size from 50 to 400 jugera, with some subdivisions using non-square plots.

Each heredium was divided in half along the north–south axis thus creating two jugera: one jugerum, from jugum (yoke), measured 2523 square metres, which was the amount of land that could be ploughed in one day by a pair of oxen.

Even today, in some parts of Italy, the landscape of the plain is determined by the outcome of Roman centuriation, with the persistence of straight elements (roads, drainage canals, property divisions) which have survived territorial development and are often basic elements of urbanisation, at least until the twentieth century, when the human pressure of urban growth and infrastructures destroyed many of the traces scattered throughout the agricultural countryside.