Calling all armchair generals! Boudica's Last Stand.

[Nathan Ross]

Oh God!  It's the cavalry dash again!

I know! It is the myth that will not die!

I thought we'd dropped the pejorative "Cavalry Dash" for Steve's more compelling, credible and accurate description of an Advanced Armed Reconnaissance Patrol in Force.

'Cavalry Dash' was originally Steve Kaye's term. Might you be thinking of Duncan Mackay's 'Relief Column'? (hard to see who they were relieving, of course, since there were no troops in London...)