Berwickshire, also known as the County of Berwick, was one of the 34 traditional counties into which Scotland was divided for administrative purposes. Most of its southern edge lay along the River Tweed and formed the north-eastern portion of the border between Scotland and England.
Berwickshire was also bordered to the south-west by the traditional county of Roxburghshire; to the west by Selkirkshire and Midlothian; and to the north by East Lothian. A tidying up of the map of counties which reduced their number to 33 in 1890 had no effect on Berwickshire, which as a result remained a county in its own right until reorganisation in 1975 swept all the counties away in favour of 12 regions.
The main settlements in Berwickshire were Lauder, Coldstream, Duns, Eyemouth and Greenlaw. The county town became Duns, after Berwick-upon-Tweed, which gave its name to the county, was permanently lost to England in 1482.
The regions formed in 1975 were the upper tier of a two tier local authority system, and the area which had formed the traditional county of Berwickshire became part of the region of Scottish Borders. Most regions were divided into a number of district council areas, and Scottish Borders had four of them. The area that had formed the county of Berwickshire became Berwickshire District, though the district was smaller than the county that preceded it, having lost Lauder and the surrounding area to the Ettrick & Lauderdale District.
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 Berwickshire is today the most north-easterly part of the unitary council area of Scottish Borders. For administrative purposes, Scottish Borders is divided into five area committee areas, which are partly based on the district council areas that preceded them. The Berwickshire area committee area inherited the boundaries of the Berwickshire District Council area.