Final answer:
Henry II is known for his establishment of the English common law, a unified system of royal courts, and the introduction of the jury system. His reforms provided the groundwork for the principles enshrined in the Magna Carta and increased the centralization of justice under the monarchy.
Step-by-step explanation:
The concepts that made Henry II well-known throughout Europe include the foundations of English common law and the royal court systems. Henry II, King of England from 1154 to 1189, introduced legal reforms that led to the creation of a unified court system, the development of common law based on local customs and royal judgments, and the inception of the jury system.
One of his most enduring legacies was the establishment of circuit courts with royal judges who moved around the country to hear cases, which ensured a more uniform application of the law. These reforms significantly diminished the judicial powers of feudal lords and increased the central control of the monarchy over justice, which was revolutionary at the time.
Furthermore, the Magna Carta of 1215, signed by Henry's son, King John, was an outcome of the political principles established during Henry II's reign. This document marked the first step in a long historical process that led to the rule of constitutional law in England.