The High Court was created by the Judicature Acts 1873–75, the general plan of which was given in chapter 1. Today its constitution is contained in the Supreme Court Act 1981, which consolidates the Judicature Acts and later amendments to them.

Its jurisdiction in civil matters is almost unlimited. Apart from a few special matters which by statute must be brought in a county court, the High Court can hear any case great or small, and can take any case that can come before a county court as well as everything that is outside county court limits. In practice, however, litigants are discouraged from taking small cases to the High Court and in practice it is only the weightier matters which are heard there. If, for instance, an action is begun in the High Court when it could have been brought in the county court, such as an ordinary trade debt, two things may happen. First, a High Court registrar or master may order the case to be transferred to a county court. This may occur if the sum in dispute is within the £5,000 limit for starting county court proceedings and, under a rule introduced in 1981 in an attempt to shift more business to county courts, it may also occur in cases with larger sums at stake if the issues of law or fact are simple.