A county palatine is an area ruled by a count palatine (or earl palatine, who may hold the higher title of duke) with special authority and autonomy from the rest of the kingdom. In feudal times, counts palatine exercised royal authority, and ruled their counties largely independently of the king, though they owed allegiance to him. In England today there are three counties which are formally palatine counties, namely, County Durham, Cheshire and Lancashire. In addition to these, Cornwall is generally considered as a County Palatine because of its position in England as a Duchy, which, according to custom has more power and independence than a Dukedom.
The Counties palatine of Durham and Chester, ruled by the prince-bishops of Durham and the earls of Chester respectively, were established by William the Conqueror. Cheshire had its own parliament, consisting of barons of the county, and was not represented in the parliament of England until 1543, while it retained some of its special privileges until 1830. The earldom of Chester has since 1301 been associated with the title of Prince of Wales which is reserved for the heir apparent to the throne or crown of the UK (though originally the throne of England).
As well as having spiritual jurisdiction over the diocese of Durham, the bishops of Durham retained temporal jurisdiction over County Durham until 1836. The bishop's mitre which crowns the bishop of Durham's coat of arms is encircled with a gold coronet which is otherwise used only by dukes, reflecting his historic dignity as a palatine earl.
Lancashire was made a county, or duchy, palatine in 1351 and kept many of its special judicial privileges until 1873. Although the dukedom of Lancaster merged into the Crown in 1399, it is to this day held separate from other royal lands, and managed by the Duchy of Lancaster. The title of Chancellor of the Duchy of Lancaster is still used by a member of the British cabinet. In Lancashire, the loyal toast is to "the Queen, Duke of Lancaster".
The king's writs did not run in these three palatine counties until the nineteenth century and, until the 1970s, Lancashire and Durham had their own courts of chancery.
At various times in history the following areas had palatinate status: Shropshire, Kent, the Isle of Ely, Hexhamshire in Northumberland, and, in Wales, the Earldom of Pembroke (until the 1536 union with England). There were also several palatine districts in Ireland, the most important of which was County Tipperary. In Scotland, the earldom of Strathearn was identified as a palatine county in the fourteenth century, although the title of Earl of Strathearn has usually been merged with the crown in subsequent centuries, and there is little indication that the status of Strathearn differed in practice from other Scottish earldoms.