Perthshire, also known as the County of Perth, was one of the 34 traditional counties into which Scotland was divided for administrative purposes. It covered a large and irregular (but very roughly circular) area in the centre of Scotland.
Important settlements in Perthshire included Perth, Auchterarder, Aberfeldy, Blairgowrie, Blair Atholl, Pitlochry, Coupar Angus, Crieff, Killin, Tyndrum, Crianlarich, Callander, Aberfoyle, Doune and Dunblane. Perthshire was bordered to the north by the traditional counties of Inverness-shire and Aberdeenshire; to the east by Angus (previously Forfarshire) and Fife, to the south by Kinross-shire, Clackmannanshire and Stirlingshire; and to the west by Dunbartonshire and Argyll. It also has a small exclave comprising Culross and Tulliallan on the north bank of the River Forth.
A tidying up of the map of counties which reduced their number to 33 in 1890 transferred ownership of Perthshire's exclave to Fife and saw Perthshire gain from Forfarshire an area around Coupar Angus. Perthshire was otherwise unaffected and remained a county in its own right until reorganisation in 1975 swept all the counties away in favour of 12 regions. Having said that, from 1929 it shared a county council with its small southern neighbour, Kinross-shire.
The regions formed in 1975 were the upper tier of a two tier local authority system, and the area which had formed Perthshire became part of Tayside Region. Most regions were divided into a number of district council areas, and Tayside had three. As part of the reorganisation much of the traditional area of Perthshire was joined with Kinross-shire to become Perth & Kinross District.
During the process, however, the area previously known as "West Perthshire" became part of Stirling District in Central Region. The area transferred to Stirling stretched from Killin in the north-east to Tyndrum in the north-west, and extended south past Crianlarich to take in Callander, Aberfoyle, Doune and Dunblane.
Regions and districts disappeared from the scene in a major reorganisation in 1996, being replaced by 32 unitary council areas. What had started out as the traditional county of Perthshire is now largely part of Perth & Kinross, though the areas transferred to Stirling District went on to form part of Stirling unitary council area.