Henry wishing to appear as a conservative took the idea of the jury from the Franks unknown in this country before the Norman Conquest the practice was used by the old Carolingian kings. Henry II. accordingly opened to litigants in the royal courts a new procedure - trial by jury. Regale quoddam beneficium .

The establishment of a system of royal courts, giving the same justice all over the country, the old diversity of local law was to be broken down, and a law common to the whole land and to all men was to take its place. Henry accordingly built up almost from nothing a complete system of royal courts, capable of absorbing a great rush of new work.

The implement to which he turned was the royal Council, the way in which governmental business was already regularly being carried out , this is the lineal descent for the Chancery and Exchequer, of Parliament, of the Common Law courts, and those Courts of Prerogative on which the Tudors and Stuarts relied. At the outset of Henry II's reign it dealt almost indiscriminately with every kind of administrative business. On the judicial side the Court of the Exchequer, which tried cases affecting the royal revenue, was beginning to take shape; but in the main the Council in this aspect was scarcely more than the King's feudal court, where he dealt justice, like any other lord, among his vassals.

The functions of the King's justices became more and more specialised, during the reigns of his sons the Council began to divide into two great courts, the King's Bench and the Common Pleas. They did not become fully separate till a century later. Thereafter, with the Court of the Exchequer, they formed the backbone of the Common Law system down to the nineteenth century. In addition, travelling justices - 'justices in eyre" - were from time to time appointed to hear all manner of business in the shires, whose courts were thus drawn into the orbit of royal justice.

The jury of Henry II was not the jury that we know , the jurymen were witnesses as well as judges of the facts. Good men and true were picked, not yet for their impartiality, but because they were the men most likely to know the truth. The modern jury , which knows nothing about the case till it is proved in court, was slow in coming. The process is obscure. A jury summoned to Westminster from distant parts night be reluctant to come. The way was long, the roads unsafe, and perhaps only three or four would arrive. The court could not wait. An adjournment would be costly. To avoid delay and expense the parties might agree to rely on a jury de circumstantibus, a jury of bystanders. The few jurors who knew the truth of the matter would tell their tale to the bystanders, and then the whole body would deliver their verdict. In time the jurors with local knowledge would cease to be jurors at all and become witnesses, giving their evidence in open court to a jury entirely composed of bystanders. By the fifteenth century the laws of evidence had developed, yet the old idea lingered, and even in Tudor times the king's jurymen might be tried for perjury if they gave a wrongful verdict.

The King had the sole right to summon a jury , accordingly he did not grant it to private courts, but restricted it to those who sought justice before the royal judges. It was an astute move. Henry had to provide means whereby the litigant, eager for royal justice, could remove his case out of the court of his lord into the King's court. The device which Henry used was the royal writ. At all costs baronial rights must be formally respected; but by straining the traditional rights of the Crown it was possible to claim that particular types of case fell within the King's province. Upon this principle Henry evolved a number of set formula, or writs, each fitted to a certain type of case; and any man who could by some fiction fit his own case to the wording of one of the royal writs might claim the King's justice. The wording of writs was rigid, but at this date new forms of writ might still be given. For about eighty years they increased in number, and with each new form a fresh blow was struck at the feudal courts. It was not until de Montfort's revolt against the third Henry in the thirteenth century that the multiplication of writs was checked and the number fixed at something under two hundred. This system then endured for six hundred years.

It is a maxim of English law that legal memory begins with the accession of Richard I in 1189. The date was set for a technical reason by a statute of Edward I. It could scarcely have been more appropriately chosen however, for with the close of the reign of Henry II we are on the threshold of a new epoch in the history of English law.

Most of Law was then unwritten, and in England much still remains so. The English statutes, for example, still contain no definition of the crime of murder, for this, like much other law, rested on the unwritten custom of the land as declared by the inhabitants the interpretation development, and application of the judges. Lawyers could only ascertain it by studying reports and records of ancient decisions. For this they had already in this early age made their own arrangements. A century after Henry's death they began to group themselves into professional communities in London, the Inns of Court, half colleges, half law-schools, but predominantly secular, for the presence of clerics learned in the laws of Rome and the Canon Law of the Roman Church was not encouraged, and here they produced annual law reports, or "Year Books", as they were then called, whose authority was recognised by the judges, and which continued in almost unbroken succession for nearly three centuries. In all this time however only one man attempted a general and comprehensive statement of the English Common Law. About the year 1250 a Judge of Assize named Henry of Bracton produced a book of nearly nine hundred pages entitled A Tract on the Laws and Customs of England. Nothing like it was achieved for several hundred years, but Bracton's method set an example, since followed

The Common Law is a set of rules, applied by the Queen's Courts, to govern behaviour, the Common Law has been built up by judges who took careful note of what others had pronounced in like cases. And the doctrine of precedent requires judges to follow earlier decisions of higher courts. In this way legal principles have emerged from groups of decisions, and although these may always be modified by new decisions, the established principles remain strong.

As an English judge in 1833 said:
'Our Common Law system consists in the applying to new combinations of circumstances those rifles of law which we derive from legal principles and judicial precedents; and for the sake of attaining uniformity, consistency and certainty, we must apply those rules, where they are not plainly unreasonable and inconvenient, to all cases which arise.'

As the Common Law became more settled and more detailed, complaints of injustice were made first to the king in his council and later to the Chancellor.

By the fourteenth century a supplement to the Common Law was needed and courts of equity emerged where cases were administered by the Lord Chancellor and later by the Court of Chancery without a jury, judgment was given in cases where to follow the strict letter of the Common Law would be contrary to natural justice. It was not, however, until the sixteenth century that the modern idea of equity appeared , this brilliant invention has proved its usefulness time and again. the recourse to general principles of justice to correct or supplement common and statute law; (superseded by the Chancery Division of the High Court in 1875 )