A legal fiction is a fact assumed or created by courts which is then used in order to apply a legal rule. Typically, a legal fiction allows the court to ignore a fact that would prevent it from exercising its jurisdiction, by simply assuming that the fact is different. This is the case with the Bill of Middlesex where the Court of King's Bench could only exercise jurisdiction over cases which took place in the historic English county of Middlesex. To allow the Court, which was the central court of the land, to take jurisdiction over other cases, parties began to plead that, along with the other facts, there had also been a trespass which occurred in Middlesex. This allowed the King's Bench to rule on the whole of the case.