When could a marriage be annulled in the Regency?

The Wedding from The Dance of Death by T Rowlandson (1816)
Wellcome Collection used under Creative Commons Licence (CC BY 4.0)I was recently asked whether non-consummation was the only reason a marriage could be annulled in the Regency era. It is a misunderstanding I have come across before.

A valid marriage could not be annulled just because it had not been consummated.

Impotency was grounds for annulment, but this was rarely claimed. Scroll down to the end of the post to see why.

In this post...