<P> The history of trial by jury in England is influential because many English and later British colonies, including the Thirteen Colonies which became the United States, adopted the English common law system in which trial by jury plays an important part . Many traditions, such as the number of members being twelve, originated in England . </P> <P> According to George Macaulay Trevelyan in A Shortened History of England (1958), during the Viking occupation: "The Scandinavians, when not on the Viking warpath, were a litigious people and loved to get together in the' thing' to hear legal argument . They had no professional lawyers, but many of their farmer - warriors, like Njal, the truth - teller, were learned in folk custom and in its intricate judicial procedure . A Danish town in England often had, as its principal officers, twelve hereditary' law men' . The Danes introduced the habit of making committees among the free men in court, which perhaps made England favorable ground for the future growth of the jury system out of a Frankish custom later introduced by the Normans ." </P> <P> The English king Æthelred the Unready issued a legal code at Wantage, which states that the twelve leading thegns (minor nobles) of each wapentake (a small district) were required to swear that they would investigate crimes without bias . These' juries' differed from the present - day kind by being self - informing; instead of getting information through a trial, the jurors were required to investigate the case themselves . </P> <P> In the 12th century, Henry II took a major step in developing the jury system . Henry set up a system to resolve land disputes using juries . A jury of twelve free men were assigned to arbitrate in these disputes . Unlike the modern jury, these men were charged with uncovering the facts of the case on their own rather than listening to arguments in court . Henry also introduced what is now known as the "grand jury", through his Grand Assize . Under the assize, a jury of free men was charged with reporting any crimes that they knew of in their hundred to a "justice in eyre," a judge who moved between hundreds on a circuit . A criminal accused by this jury was given a trial by ordeal . Under the jury, the chances of being found guilty were much lower, as the king did not choose verdict (or punishment). </P>

Who was the english king who introduced the use of juries