News flash! Ronda Rousey and Miesha Tate don't like each other very much.

For the last two years, Tate and Rousey have had one of the ugliest, most bitter rivalries in MMA, and it's an affair that has budded into an all-time great. It's a feud that has been building steadily ever since the two were announced as opponents for the first time almost two years ago.

So what events led to this? What are some of the most memorable, interesting moments that took place between the two? How did it all come to this!?

Find out right here!

The Strikeforce Weigh-in "Headbutt"

MMA has had many wars of words. Rashad Evans vs. Quinton Jackson. Matt Mitrione vs. Tito Ortiz. Matt Hughes vs. everyone, ever. 

Few rivalries, though, have had a moment as iconic as the dueling foreheads of Ronda Rousey and then-champion Miesha Tate. 

During the weigh-ins before their fight, hot on the heels of a lengthy war of words, Tate tried to intimidate Rousey by entering her personal space. Rousey, though, had none of that, and shoved her back in a way that drew Tate's indignation (a sign of things to come).

Bryan Caraway Makes an Ass of Himself

Few things go over more poorly in a public setting than a man threatening violence against a woman. So when Bryan Caraway, Tate's long-time boyfriend, took to Twitter to say he'd knock in Ronda's teeth after the weigh-in "head-butt" incident, it was unsurprisingly met with sweeping criticism.

That set the stage for a lot of the drama on The Ultimate Fighter season 18 (more on that later). 

While what Caraway said was downplayed to an irresponsible degree due to his consistent presence near bantamweight title contention, there was no downplaying how it played out on TUF. When Rousey and her coaching staff finally got access to Caraway, they ripped into him as hard as possible. 

While Tate and Caraway instantly downplayed the incident, the damage was done and may or may not be reversible. 

Rousey Breaks Tate's Arm, Brags About It

While the "headbutt" was an iconic moment for this individual rivalry, Rousey rotating Tate's arm 90 degrees in the wrong direction was a sight that, quite possibly, single-handedly changed the course of women's MMA forever.

Rousey masterfully working top position before taking hold of Tate's arm gave women's MMA two things it had lacked to that point: a truly elite champion and undeniable proof that women's fights were every bit as intense and fierce as the men's equivalent. 

Was it a good day for Tate? Absolutely not. That said, seeing her arm move in a direction it simply wasn't supposed to set up women in the UFC, and the renaissance that has accompanied that change.

The Rematch Is Set!

As I'm sure all of you know, Miesha Tate wasn't supposed to be fighting Ronda Rousey tonight. That honor was supposed to belong to Cat Zingano, who beat her back in April at the TUF17 Finale. 

While Zingano undeniably earned her spot against Rousey, just like with Nick Diaz and Georges St-Pierre, there is just no ignoring the undeniable appeal of an ugly rivalry, even if there are greater on-paper contenders. It also doesn't hurt that, for the actual coaching job, Tate is among the most well-networked female fighters in MMA, which allowed her to bring in numerous high-level coaches. 

But again, Tate was selected entirely because of the fact that her and Rousey combine for must-see TV. 

The Press Tour Middle Finger

Chronologically, things get a little bit warped here (since TUF18 had already been filmed, didn't start airing until after this happened), but this was a sample of the ugliness that fans could look forward to on Fox Sports 1. It was also the most recent instance of Tate getting a good view of Rousey's middle digit.

Obviously, six weeks' worth of time with a woman she didn't like, and taking personal swipes at her coaches and friends didn't do much to improve their relationship. However, Rousey made no effort to hide her newly reignited hatred for Miesha Tate.

This incident built interest in TUF18. TUF18, in turn, built anticipation for tonight's epic rematch.

Make sure to stick with Bleacher Report for all our UFC 168 coverage!