In the olden days they would unless you flicked a switch on the drawbar to block it. Modern caravans have trickery in the braking system that automatically blocks them.
Modern caravans have trickery in the brake system, My first caravan was a 1960 Schult 10ft made by Tancrest long long since gone it had auto reversing.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.