The Heritable Jurisdictions (Scotland) Act 1746 (20 Geo. II c. 43) was an Act of the British Parliament passed in the aftermath of the Battle of Culloden, which fateful clash brought the Jacobite Rising of 1745 to a prompt end.
Traditionally, Scottish lords and clan chiefs had inherited regalities and been able to judge in civil and criminal cases among their dependants. The Act put an end to this by extending universal royal jurisdiction throughout Scotland. The powers previously possessed by Scottish lords were transferred to sheriffs appointed by the King and the hereditary justiciarship of Scotland, held by the family of Campbell of Argyll, was to be purchased and transferred to the High Court and Circuit-courts of Justiciary. Parliament granted £152,000 for the purchase of heritable jurisdictions. The Prime Minister Henry Pelham considered this the most important measure in suppressing Jacobitism in Scotland.
* * *
In Scotland, Justiciars were the king’s lieutenants for various judicial and administrative purposes. The office was established in the XII century, either by Alexander I or by his successor, David I.
The title of ‘Justiciar’ was reserved for two or three high officials, the chief one — the Justiciar of Scotia — having his jurisdiction to the north of the River Forth. The Justiciar of Lothian dealt with the part of the kingdom south of the Forth-Clyde line.
The role of Justiciar evolved into the current Lord Justice-General, the head of the High Court of Justiciary, head of the judiciary in Scotland and a member of the Royal Household.
The present Duke of Argyll, His Grace Torquhil Ian Campbell, Chief of Clan Campbell, still holds the hereditary title of High Justiciar of Argyll, but no responsibilities now attach to it.