There is one reputedly fifth-century document of which numerous fragments survive and which purports to offer important contemporary evidence for Roman social and economic structures in this period. This is the Twelve Tables, the law-code assigned to circa 450 BC. The compilation of the Tables is attributed to two ten-man commissions (decemviri legibus scribundis) which replaced the consulship as the chief magistracy in 451 and 450 BC. To the limited extent that later writers concerned themselves with economic matters they saw early republican Rome as essentially a farming community. Early Rome practised settled agriculture based on a prevalence of comparatively small-scale, privately owned farms which provided the fundamental resource of the great majority of the citizen body. Hence not only does the primacy of the family unit reflect this pattern of economic activity but the entire structure of kin-group classification and the regulation of kin prerogatives show a pre-eminent concern with the transmission of property.