From 1885, it administered Scotland on behalf of the government and survived the re-establishment of the Scottish Parliament to remain an outpost of Westminster authority north of the border.
But in name at least, the 133 year-old Scotland Office now appears to have vanished, falling victim to a corporate re-branding exercise that has claimed its historic identity.
The department once presided over by Donald Dewar and Tom Johnston is now officially known on Whitehall by the less snappy name of the ‘Office of the Secretary of State for Scotland’.
Government work on behalf of Scots continues at Dover House, the Scotland Office’s historic home, but the brass plaque outside the door now reads ‘Secretary of State for Scotland’ - now the job of Borders MP David Mundell.
The changes were made without fanfare. Journalists were only alerted to the re-branding when the disappearance of the words ‘Scotland Office’ beneath the coat of arms in emails set unicorns running.
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Social media channels belonging to the department were changed in 2015 so that the department’s public face became the ‘UK Government in Scotland’, but at the time officials denied a wider re-branding would take place.
Since late 2017, however, official websites and communications have carried the new identity.
The changes also extend to the Wales Office, which is now the Office of the Secretary of State for Wales - although officials at its HQ opposite Dover House seem more ambivalent about the re-branding, relegating the new name to a subheading in parentheses on the plaque by the door.
With more pressing issues on its agenda, the Northern Ireland Office continues as it was.
Officials at the department formerly known as the Scotland Office insist that it continues to exist, and that its new identity is intended to promote the breadth of the UK Government’s work in Scotland.
The changes were implemented to underline the fact that other Whitehall departments also work north of the border - and to avoid any confusion with the Scottish Government.
Asked whether the government had downgraded one of its departments, the Prime Minister’s spokesman said: “The Scotland Office continues to do the work the Scotland Office has always done.”
A UK government spokeswoman said: “The Scotland Office updated its corporate identity some time ago. The change ensures people can be confident about which responsibilities the UK Government delivers and are able to identify which issues have been devolved.
“This will make clear the extensive role of the UK Government in delivering for people in Scotland.”
In 1999, the re-establishment of the Scottish Parliament saw the department formally dissolved as most of its responsibilities were transferred to Holyrood. Its former HQ at St Andrews House in Edinburgh now houses Scottish Government offices. Having previously been officially known as the 'Scottish Office', the department was reformed as the Scotland Office.