(The). The 5th Dragoon Guards; so called because they are a
horse regiment, and have green for their regimental facings.
Now called “The Princess Charlotte of Wales's Dragoon Guards.”
Tarleton's green horse.
That is, the horse of General Tarleton covered with green ribbons
and housings, the electioneering colours of the member for Liverpool,
which he represented in 1790, 1796, 1802, 1807. His Christian name was
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894