My dad was born in Cleethorpes, home of Grimsby Town. Lincolnshire folk then were known as 'yellowbellies'.
I think it has something to do with the selling of horsemeat. Arnold Drury appears to have been the last British butcher to officially do this sometime back in the 40's. Tescos thus taking over this role.
The Sikhs used them in Burma during WWII against the Japanese - do Colonial Forces count as British Army?
The Battle of Rooiwal during the Boer War in 1902?
I would imagine early in the start of WW2 on the road back to Dunkirk?
No, actually later than this. A clue is that my father was affected by this. This military action is not that well known but the records come from the Chelsea military hospital - a couple of the Dragoons involved in this action are still alive and at Chelsea.