Court of Great Sessions in Wales

The Court of Great Sessions in Wales was the main court for the prosecution of felonies and serious misdemeanours in Wales between the second Laws in Wales Act of 1542 and the court's abolition in 1830. It had the same powers in civil law as the King's Bench in England, (it also had equity jurisdiction) and its criminal jurisdiction was equivalent to the English county assizes.

The Court was established under the 1542 Act which formally incorporated Wales within the English legal system. Of the 13 Welsh counties, 12 – that is, all except the County of Monmouth – formed new court circuits. These were Chester (comprising the counties of Flint, Denbigh and Mountgomery); North Wales (Anglesea and the counties of Caernarvon and Merioneth); Brecon (the counties of Brecon, Glamorgan, and Radnor); and Carmarthen (the counties of Kayermarthen, Cardigan, and Pembroke). Monmouthshire was added to the Oxford circuit of the English Assizes. The Sessions met twice a year in each county, administering English law in the English language: of the 217 judges who sat on its benches in its 288 years of existence, only 30 were Welshmen and it is unlikely that more than a handful of the latter – members of the higher gentry – actually spoke Welsh.

...
Wikipedia