I saw this on TV in the 1970s. Probably a sixties film but could also be from the 1950s.
It was an adventure film set in the middle ages, possibly around the time of the Norman conquest.
A woman distracts a group of warriors on horseback by disrobing. This is shown with a cutaway to her feet as her clothes drop to the ground, followed by shots of the men laughing at her. Extended scenes of the siege of a castle follow.
I enjoy epic adventure movies anyway (will watch just about any of them) and always thought I would eventually stumble across this again one day but I never have.
Does this ring a bell with anyone?