History of jurisdiction
During the Roman occupation of Britain, the area of present-day England and Wales was administered as a single unit, with the exception of the land to the north of Hadrian's Wall - though Britannia eventually extended to the Antonine/Severan Wall. At that time, most of the native inhabitants of Roman Britain spoke Brythonic languages, and were all regarded as Britons, divided into numerous tribes. After the conquest, the Romans administered this region as a single unit, the province of Britain.
After the departure of the Romans, the Britons of what became Wales developed their own system of law, first codified by Hywel Dda (Hywel the Good; reigned 942–950) when he was king of most of present-day Wales, while in England Anglo-Saxon law was initially codified by Alfred the Great in his Legal Code, c. 893. However, following the Norman invasion of Wales in the 11th century, English law came to be practised in the parts of Wales conquered by the Normans (the Welsh Marches). In 1283, the English, led by Edward I, with the biggest army brought together in England since the 11th century, conquered the remainder of Wales, then organised as the Principality of Wales, which was united with the English crown by the Statute of Rhuddlan of 1284. This aimed to replace Welsh criminal law with English law.
Welsh law continued to be used for civil cases until the annexation of Wales to England in the 16th century. The Laws in Wales Acts 1535–1542 then consolidated the administration of all the Welsh territories and incorporated them fully into the legal system of the Kingdom of England.
Prior to 1746 it was not clear whether a reference to "England" in legislation included Wales, and so in 1746 Parliament passed the Wales and Berwick Act. This specified that in all prior and future laws, references to "England" would by default include Wales (and Berwick). The Wales and Berwick Act was repealed in 1967, although the statutory definition of "England" it created is preserved for acts passed prior to its repeal. Since the Act's repeal what was referred to as "England" is now "England and Wales", while references to "England" and "Wales" refer to those political divisions.