King Henry II established many basic principles like-
1- Assize of Clarendon that established the grand jury system for investigating crimes. Earlier it was ordeal for punishing the criminals but later it was disapproved by the Church so the jury system came to practice.
2- Assize of Northampton that established the jury of presentment to decide which cases should be tried.
3- Assize of Arms that ordered that all free men should keep arms and be prepared to defend the country.
