Ronda Rousey and Gina Carano are arguably the two biggest leaders in bringing women's mixed martial arts to the mainstream. Furthermore, they're also the two biggest female stars to have ever competed in the cage. Both women have exited the cage to success in acting and pro-wrestling (in the case of Rousey).

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However, the two women never met in the cage. Despite having some career overlap and having a reported bout on the books for December 2014, it never happened. It's a bit long and complicated, but here's the story behind two of the biggest female MMA fighters never facing off.

8 Carano's Rise

Gina Carano began fighting in 2006, making her debut against Leiticia Pestova in a fight she won via KO. Within two years of competing she quickly racked up a 8-0 professional record. She made her Strikeforce debut in her third pro bout, defeating Elania Maxwell. However, Strikeforce didn't retain her after the bout.

What was Strikeforce's loss, was EliteXC's gain. The promotion saw something in Carano, and signed her to an exclusive deal. She was quickly inserted onto the main card for all of her bouts moving forward. She made history as the winner of the first-ever nationally televised female MMA bout when she beat Julie Kedzie via unanimous decision in 2007.

7 Rousey's Run In The Olympics

While Gina Carano was making her name in MMA, Ronda Rousey was establishing herself in Judo. The lifelong Judoka trained her entire life for one moment, the 2008 Olympics. In the Bejing games, 'Rowdy' would make history.

It was her second attempt at winning a medal, after falling short in 2004. This time, she made the most of her second chance. She captured a bronze medal in the summer games, and in the process became the first American woman to capture a medal in Judo.

6 Gina Carano's Fight With Cris Cyborg

Following EliteXC's closure, and the UFC not having a women's division, Gina Carano signed to Strikeforce once again. She quickly was given a title fight against the dominant future women's featherweight champion Cris Cyborg. The fight was set to crown the inaugural Strikeforce female 145-pound titlist and was the first time two women headlined a major MMA event.

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Carano was the underdog heading in but found success in the grappling early. However, Cyborg quickly turned the momentum around and scored a dominant knockout victory over Carano. Following the bout, the star announced she would be taking some time off.

5 Rousey Begins Her MMA Career

While Carano was taking time off, Ronda Rousey's career was just beginning. She began her amateur career less than a year after Carano's bout against Cyborg, and quickly wracked up a 3-0 amateur record. She then earned two victories on the regional scene before being signed to Strikeforce.

She was signed to Strikeforce as a short-notice replacement in 2011. In a weird twist of fate, 'Rowdy' was being brought in to compete against Sarah D'Alelio after Gina Carano pulled out of her bout against her. The Rousey/D'Alelio matchup was pushed back a few months, but the future champion won the bout via submission.

4 Rousey's Rise To Stardom

Whenever Carano pulled out of her fight with D'Alelio in 2011, she then turned away from MMA completely to focus on acting. In that timeframe, Ronda Rousey became the biggest star in the sport. Less than a year after she signed to Strikeforce, she won gold after defeating Miesha Tate via submission.

'Rowdy' began making waves in the sports world, by racking up dominating wins in the Strikeforce cage. Not much longer, the UFC had decided to bring in Rousey and the entire Strikeforce bantamweight division after buying out the company. By 2014, she was arguably the biggest star in MMA.

3 Discussions Of A Possible Rousey vs. Carano Bout

In April 2014, Gina Carano publicly announced that she was looking at a return to the cage. Having been a Strikeforce fighter, her contract already made her a UFC athlete when the company was bought out. With Rousey's marketability, the promotion quickly began looking at making a fight.

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The two sides began negotiating, and the bout even had a planned date of December 2014. UFC 181 went on to be an excellent card featuring Robbie Lawler and Johny Hendricks 2, but it was supposed to be so much more.

2 Fight Plans Fall Apart

Dana White has maintained that of all the fighters he's had to deal with, Gina Carano was the absolute hardest to deal with. At one point, the UFC president opined that he only had a few more hurdles to climb to make the fight, but by September 2014 the fight was dead in the water.

White noted that the difference in an MMA manager and an acting manager likely played into the issue with talks. As the UFC president noted that they had massive differences in negotiating, prices, and knowledge of the sport. With Carano out, the UFC instead had Rousey fight Cat Zingano in February 2015.

1 Unlikely To Ever Happen

In the sport of MMA, it's hard to say that something absolutely won't happen. Ken Shamrock and Royce Gracie's trilogy bout took 21 years to happen, for one example. However, it seems that Ronda Rousey vs. Gina Carano is in the category of fights that fans missed out on.

Both women seem to be firmly in retirement. While both are still only in their 30s, Rousey seems happy to be in the world of pro-wrestling, and Carano seems happy to be acting. Neither have mentioned MMA much since their exits from the sport.