Should you invite your ex to the wedding?

Would you invite your ex to your wedding? Would you mind your soon to be spouse invite their ex to the wedding? It is hard enough trying to plan a wedding or even the party to follow now you have to think about if you should or shouldn't invite your ex.  There are good reasons to invite them but, there are some reasons why you shouldn't.  

One of the requirements if you do decide to take such a leap you must have an understanding mate to pull this off.