Kevin Costner and Christine Baumgartner seemed destined to fight out their divorce for months to come in court — but now that anger-fueled ride’s come to a screeching halt with their settlement … which makes this look-back at how they got here all the more eye-popping.

Going all the way back to early May — when CB first filed to end their marriage — this uncoupling had all the markings of being ugly, starting with the fact her decision to divorce Kevin completely blindsided him.

What proceeded over the next 5 months amounted to one of the nastiest celeb divorces in recent memory … despite the fact they had a prenup in place.

Pretty much from the jump, Christine indicated she had plans to challenge the validity of the prenup — starting with the fact she put up a fight about moving out of their house … even though the prenup required her to get out if she were to divorce him.

After A LOT of back and forth in court and judge’s ruling … Christine did move out by the court ordered deadline in late July. Keep in mind, Kevin said he’d already given her over a million bucks to get her own pad.

In addition to the housing drama … there was the acrimonious issue of child support, which had been challenged by Christine since the beginning. At first, she’d asked a judge to make Kevin pay a whopping $248,000/month to support their 3 teenage kids.

Kevin, of course, scoffed at that … insisting the realistic number was probably closer to $63k/mo. — and while he had to cough up $129k/mo as interim amount, the judge ultimately sided with him on this matter, ruling the $63k was enough to sustain the children.

Amid all this mudslinging and money talk, the Costners went on vacation — 2 different ones, actually … and their kiddos got to enjoy respective trips with Mom and Dad. Christine took them to Hawaii for a week, and then KC flew them out to Aspen for some QT.

Come August, it was back to the lawyers’ table … with both Kevin and Christine sitting for a deposition to settle the issue of whether Christine “understood” the prenup she signed way back before their 2004 wedding … something she and her lawyers argued might not have been totally clear to her.

Kevin and Christine showed up dressed to the nines for that depo … and then testified all over again in court to hash out more points, including money, rumored partners and more.

In the end, a judge sided with Kevin on this as well — saying the prenup was clear, and ordered Christine to pay a little more than $14k to cover Kevin’s attorney fees for litigating this minute detail.

Christine then signaled she wasn’t done nitpicking … asking for more cash from Kevin to cover her attorney fees, which she estimated at $885k.

That was the latest barb just a few days ago … and there appeared to be no end in sight. Then, just this week, Christine and Kevin buried the hatchet in a surprise move.

As we reported … they settled, the terms of which are being kept private for now. While Christine seemed to be taking L after L in court, it sounds like she might’ve clocked a small win in the end — as our sources tell us she walked away with more dough than what she was due under the original terms of their prenup.