Mary, Queen of Scots.

I don't know the story behind Glenda Jackson playing Elizabeth again. Not as good as Elizabeth R, although the depiction of Mary's personality is skillfully shaded and the production values are magnitudes plushier. Several risible bits that presage Holy Grail. I now think that John Cleese was in fact parodying the portrtayal of John Knox from this movie. There are also ground-to-parapet conversations that may have been shot at the same castle. Patrick McGoohan has a slithery role.