Maybe one astride a heavy carthorse? (9)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

if someone was perching on a horse, s/he might be said to be astride it; a Percheron is a compact heavy breed of carthorse; Le Perche (after which it is named) is a former province of France approximately occupying a place in modern-day south-east Normandy