Ok, let's stop and consider some points here.
I get the impression that she is still married...if so, why? A divorce should be the first thing to consider, here...
Second, it sounds alot like she has 'Battered Woman syndrom'...and unless you have a lot of experience in dealing with such cases (and it doesn't sound like you do), then she needs to get into councilling as soon as possible...and the only thing you can really do that would be helpful here is to be supportive and understanding...even if the relationship 'fails' because of it (which is a real possibility).
Third, are there children involved here? I hope not...otherwise, you have the worst case scenario here...without a 'quick' solution in sight...
Fourth, does her family know, and are they involved? Are they supportive (of her)? If they don't know, they need to know...you both need all the support and help that you can get. If they know, but don't want to get involved, you have a problem...especially if they are not supportive (of you).
The next bit of advice may be hard to swallow...but you need to consider it.
You need to do some 'house-keeping'...that means you need to set some priorities, and get some things straight. First of all, you need to consider the above points. That comes first. Next, you need to get your head together...you (and her) are probably (and it sounds like it, why else would you ask us for advice?) in emotional turmoil, which is a very hard place to think straight from. The advice from Moaiz has some good points...know your enemy. Information and evidence is the key here. Collect as much as you can and save it! It may become crucial to whatever court stuff you may have to go through...hearsay is not very good evidence...
Also, you need to consider the fact that this guy (the husband?) may be dangerous. Know what you are up against...many have paid a terrible price because they underestimated the danger...don't be unrealistic. It's very easy to get a weapon...and because he has already demonstrated that he can and will use violence to establish his will, you need to consider that.
Ok, then you need to consider how you wish to handle the situation...are you going to take the High ground, or the Low ground?
The High ground...doing it the legal way. First, the divorce (if it hasn't already been done). That's a must. This will solve a few things. It will 'cut' the last legally binding ties, and will then give you a small advantage...of the moral question. Right now, you are 'morally' in the wrong...if she is still married (I know, that sounds wrong, but think about it...what if it was your wife, and she told this other guy the same story that you have heard...how do you think you would react?). Then the restraining order as soon as you can get it...do you have evidence of the battering? Pictures, witnesses, medical reports, anything. I sincerely hope that you do...because not only will it help in court, but it will also remove any questions of lying...which is very important (trust me on this...I've gone through this type of stuff a lot...and seen a hell of a lot more...and my mother works in a shelter for battered women).
Well, Moaiz pointed out the Low ground pretty well...so I won't go into that (BTW Moaiz, I've re-evaluated you...I have now put you in the 'very serious' catagory of people...and there are not that many I've put in that one...)
As for the 'protective' role...it seems to me that you've already taken it...whether or not you realize that. Moiz hit the nail on the head when he questioned her motives...as she is coming from a 'destructive' relationship (and that is apparently the case, as you say she has/had very low self-estiem)...many women that have gone through such a traumatic experience often confuse love with kindness/gratefullness...and this confusion is inside...that's why I suggested councilling...it could be that she needs some time to live alone...to get herself sorted out, and to get her feet under herself...not very conducive to a relationship at the moment...but if she really loves you, then that won't change. Time can be a great ally...especially in situations like this (thus the understanding and supportive part...it may be that you will have to let her go to do this).
Now, why is that? Well, women (and men, as well, though it's a lot less talked about) coming from a traumatic relationship, esp. a violent one, have a raised tolerance for abuse i.e. for them, abuse has become 'normal' (and therefore, a 'sign' of love)...and non-abuse (love, kindness, etc) is 'not normal' (and therefore, not a 'sign' of love)...and the same goes for the abuser. Of course, I don't know how long she has been in an abusive environment...but most such environments start back in childhood...otherwise, she most probably wouldn't of stayed in the relationship...(however, it differs from case to case...get her into councilling now! And you could inform yourself on this, there is plenty of information out there...)
So you are in a very difficult situation...on the one hand, you have stress from without...on the other, stress from within. You need to gather as many allies as you can...also, getting her away from the abuser and into counciling can only be good for her...and for you (though it may not seem like it, it really is the best way to go).
[This message has been edited by WebShaman (edited 07-15-2002).]