The ancient common law system of England is still prevalent in many nations associated with—or previously associated with—the United Kingdom, not simply in England and Wales. Findings of fact at common law were the sole prerogative of the jury for many centuries. This chapter addresses restraints upon jurors’ conduct and jury verdicts that evolved over many centuries, imposed by an increasingly active judiciary in the interest of preventing injustices stemming from jury verdicts that were unsupported by competent evidence, biased, or otherwise should not be allowed to stand in the interests of justice.