<P> The roots of the legal principles and practices of the ancient Romans may be traced to the Law of the Twelve Tables promulgated in 449 BC and to the codification of law issued by order of Emperor Justinian I around 530 AD (see Corpus Juris Civilis). Roman law as preserved in Justinian's codes continued into the Byzantine Empire, and formed the basis of similar codifications in continental Western Europe . Roman law continued, in a broader sense, to be applied throughout most of Europe until the end of the 17th century . </P> <P> The major divisions of the law of ancient Rome, as contained within the Justinian and Theodosian law codes, consisted of Ius Civile, Ius Gentium, and Ius Naturale . The Ius Civile ("Citizen Law") was the body of common laws that applied to Roman citizens . The Praetores Urbani (sg . Praetor Urbanus) were the people who had jurisdiction over cases involving citizens . The Ius Gentium ("Law of nations") was the body of common laws that applied to foreigners, and their dealings with Roman citizens . The Praetores Peregrini (sg . Praetor Peregrinus) were the people who had jurisdiction over cases involving citizens and foreigners . Ius Naturale encompassed natural law, the body of laws that were considered common to all beings . </P> <P> Ancient Rome commanded a vast area of land, with tremendous natural and human resources . As such, Rome's economy remained focused on farming and trade . Agricultural free trade changed the Italian landscape, and by the 1st century BC, vast grape and olive estates had supplanted the yeoman farmers, who were unable to match the imported grain price . The annexation of Egypt, Sicily and Tunisia in North Africa provided a continuous supply of grains . In turn, olive oil and wine were Italy's main exports . Two - tier crop rotation was practiced, but farm productivity was low, around 1 ton per hectare . </P> <P> Industrial and manufacturing activities were smaller . The largest such activities were the mining and quarrying of stones, which provided basic construction materials for the buildings of that period . In manufacturing, production was on a relatively small scale, and generally consisted of workshops and small factories that employed at most dozens of workers . However, some brick factories employed hundreds of workers . </P>

What was the relationship between the roman territories and the city center