Calling all military historians and forces enthusiasts – can you provide us with any information about this photograph?

Clearly, it shows the late Queen Mother at some sort of military event or celebration but what was the occasion? 

We know the Queen Mum visited Hampshire during the war to see troops in training at Aldershot, but this picture appears to have been taken much later than that.

The building in the background looks like a church, but where is it exactly? 

And to what regiment do the men seated with the royal belong?

Please email [email protected] with any answers.