The regiment was originally formed as part of the Imperial Yeomanry in November 1901, as the 4th County of London Imperial Yeomanry (King's Colonials), with the Prince of Wales (later King George V) as honorary colonel.
In 1905 it was retitled The King's Colonials, Imperial Yeomanry, and in 1908 became part of the Yeomanry in the Territorial Force. In 1909 the specific affiliations of the squadrons ended. With the death of Edward VII, after whom it had been named, it was retitled King Edward's Horse (The King's Overseas Dominions Regiment) in 1910. In 1913, it was transferred into the Special Reserve, and ceased to be considered yeomanry.
This is one of three badges King's Colonials worn on their hat.
Badge displaying the initials "KC" below the Prince of Wales plumes, coronet and motto in brass, was used to secure the turned up left brim.