Historical Timeline of Legal Systems By cheerfox 300 Code of Hammurabi This was the first known system of written law 450 Roman Law Roman law was published in 450 BC; as the empire grew, laws spread to Europe, Africa, and Asia. Period: 500 to Jan 1, 1850 The Sources of our Laws 533 Justinian code Justinian 1, the ruler of the Bysantine Empire shortened Roman Law into the Code of Justinian. Mar 20, 1066 Common Law Common Law was based on court decisions rather than on legal code. The law came to include principles such as citizens' right to a trial by jury, and all people are innocent until proven guilty. Mar 20, 1787 US Constitution In 1787, our founding fathers all sat down, and wrote a list of principals, thats known the world around. The USA was just starting out a whole new country. And so our people spelled it out they wanted a land of liberty. Mar 20, 1804 Napoleanic Code Napolean updated the justinian code and calledit the napoleanic code.