<P> Colonial expansion spread the civil law system . </P> <P> Today, Roman law is no longer applied in legal practice, even though the legal systems of some countries like South Africa and San Marino are still based on the old jus commune . However, even where the legal practice is based on a code, many rules deriving from Roman law apply: no code completely broke with the Roman tradition . Rather, the provisions of the Roman law were fitted into a more coherent system and expressed in the national language . For this reason, knowledge of the Roman law is indispensable to understand the legal systems of today . Thus, Roman law is often still a mandatory subject for law students in civil law jurisdictions . </P> <P> As steps towards a unification of the private law in the member states of the European Union are being taken, the old jus commune, which was the common basis of legal practice everywhere in Europe, but allowed for many local variants, is seen by many as a model . </P>

The 5th-century bc corpus juris civilis was the first body of written law in rome