The Portsoken Volunteers is part of the City of London Home Guard formed in the late 18th Century to defend London against a Napoleonic invasion. This Company still exists today and the Uniform is the same as that used in the time of King George III, though they are now

CO of the Portsoken Volunteers
only deployed for ceremonial duties.
The CO asked me to do a portrait of him for part of my final year’s work, which is rather fun, but will be a long, multi-stage job.
Here is a drawing I did of him relaxing, in his splendid uniform.