Unfortunately you need this certificate no matter how many marriages you've had. If you're divorced, as I remember, you'll need a copy of the divorce decree as well, and widows/ers will need a death certificate I think. My marriage is my first (and hopefully only!) marriage and I still needed this document to prove I was single.
ETR I thought it was absolutely ridiculous that I needed my passport translated as well but sure enough, we turned up the first day without it and had to go back and get it done before we could get married. It took only one day to get the translation if I remember correctly, rush service.