The common law.
As for the petty or smaller jury, which actually tried the accused, its origin and history are obscure. It did not originate with Henry II, but he systematized trial by jury and made it a settled law of the land instead of an exceptional favor. The plan of delegating the duty of determining the guilt or innocence of a suspected person to a dozen members of the community who were sworn to form their opinion without partiality was very different from the earlier systems. It resembled neither the Roman trial, where the judges made the decision, nor the mediæval compurgation and ordeals, where God was supposed to pronounce the verdict. In all legal matters the decisions of Henry's judges were so sagacious and consistent that they became the basis of the common law which is still used in all English-speaking countries.
Henry II and Thomas à Becket.
Becket as chancellor.
Henry's reign was embittered by the famous struggle with Thomas à Becket, which illustrates admirably the peculiar dependence of the monarchs of his day upon the churchmen. Becket was born in London. He early entered one of the lower orders of the Church, but grew up in the service of the crown, and was able to aid Henry in gaining the throne. Thereupon the new king made him his chancellor. Becket proved an excellent minister and defended the king's interest even against the Church, of which he was also an officer. He was fond of hunting and of warlike enterprises and maintained a brilliant court from the revenues of the numerous church benefices which he held. It appeared to Henry that there could be no better head for the English clergy than his sagacious and worldly chancellor. He therefore determined to make him Archbishop of Canterbury. The kings of that time often chose their most efficient officers from among the prelates. Lanfranc, for example, had been the Conqueror's chief minister. There were several good reasons for this practice. The clergy were not only far better educated than laymen but they were also not ordinarily dangerous as military leaders, nor could their offices become hereditary.
Made Archbishop of Canterbury, Becket defends the cause of the Church against the king.
In appointing Becket Archbishop of Canterbury, Henry intended to insure his own complete control of the Church. He proposed to bring clerical criminals before the royal courts and punish them like other offenders, to make the bishops meet all the feudal obligations, and to prevent appeals to the pope. Becket, however, immediately resigned his chancellorship, gave up his gay life, and opposed every effort of the king to reduce the independence of the Church. After a haughty assertion of the supremacy of the spiritual power over the secular government, Thomas fled from the wrathful and disappointed monarch to France and the protection of the pope.
Murder of Becket and Henry's remorse.
In spite of a patched-up reconciliation with the king, Becket proceeded to excommunicate or suspend some of the great English prelates and, as Henry believed, was conspiring to rob his son of the crown. In a fit of anger, Henry exclaimed among his followers, "Is there no one to avenge me of this miserable clerk?" Unfortunately certain knights took the rash expression literally, and Becket was murdered in Canterbury cathedral, whither he had returned. The king had really had no wish to resort to violence, and his sorrow and remorse when he heard of the dreadful deed, and his terror at the consequences, were most genuine. The pope proposed to excommunicate the king. Henry, however, made peace with the papal legates by the solemn assertion that he had never wished the death of Thomas and by promising to return to Canterbury all the property which he had confiscated, to send money to aid in the capture of the Holy Sepulcher at Jerusalem, and to undertake a crusade himself.[92]
Richard the Lion-Hearted, 1189–1199.