In the 1970s, John Travolta urged on by his wife Mimi Rogers, joined the Church of Scientology. L. Ron Hubbard, the founder, and leader of the Church was thrilled. Travolta was one of his first high-profile celebrity converts. The Church bent over backwards to keep Travolta happy.

It didn't last. In the 1980s a younger and up and coming actor by the name of Tom Cruise joined the Church. The star of such movies as Top Gun was welcomed with open arms. Rumor had it, early on, that the two did not get on. Specifically, it was said that Cruise did not like Travolta and his then-partner actress Kirstie Alley.

So, is the feud between the two real? In a couple of words: Almost certainly. You can only have one top Church dog and both Travolta and Cruise believe they are it. But the facts say differently.

Despite the fact that the Church probably had a hand in wrecking his marriages to Nicole Kidman and Katie Holmes, Cruise has remained rabidly loyal to the Church and its new head David Miscavige. Former members have spilled the beans on Travolta's frustration with the preferential treatment Cruise receives from the Church and its leader. In public, it's all smiles and buddy-buddy. But behind the scenes, the two have been squabbling and feuding for years.

Here comes proof that the feud between Cruise and Travolta is very, very real.

Cruise Got The Church's Top Award And Travolta Seethed

Brendan Tighe, a former lifelong Church member, was part of Tom Cruise's security detail, a perk provided by the Church. He says that when Tom Cruise was awarded The Freedom Medal of Valor, the Church's top award, in 2008, Travolta went berserk. Why not me? Why him?

RELATED: What Was Tom Cruise's Life Like Before He Became Famous?

Tighe has spilled the beans and said that Travolta was beside himself when Cruise got the Medal: “It’s no secret that Cruise and Travolta despised each other. I can assure you Travolta doesn’t recognize Cruise as a superior in any way. When Cruise got that medal, Travolta was so pissed off.”

So, the feud goes way back, almost from the beginning of Cruise's time as a member.

Leah Remini's Tell-All Book

Actress Leah Remini was a big Scientologist, but she defected in 2013 and in 2015 wrote a book, Troublemaker: Surviving Hollywood and Scientology. You can probably tell from the title that she's not a big fan of the Church of Scientology. She dished a lot of dirt, saying that she had been part of Tom Cruise's Church inner-circle and was surprised that John Travolta and Kirstie Alley weren't part of it as well. She was told in no uncertain terms that Cruise didn't like Travolta or Alley. They were O-U-T.

She also said that Travolta wasn't even invited to Cruise's wedding to Katie Holmes. She has also said that the Church made certain Tom Cruise got everything he want when he wanted it.  She and her husband were ordered to give Cruise the salsa lessons he was demanding. Trust us. John Travolta didn't receive the same level of attention!

RELATED: 15 Things Leah Remini Has Been Up To Since Scientology And The Aftermath

Plus, when Cruise broke up with wife Nicole Kidman, David Miscavige reportedly held "auditions" for a new girlfriend for Cruise. It was rumored that Scarlett Johansson was auditioned. She hotly, loudly, and publicly denied it. Apparently, the Church was so over-protective of Cruise that they had spied on and followed Nicole Kidman. It probably played a role in the break up of his marriage.

Travolta, all loved up with fellow Scientologist Kelly Preston, was and is angry about Cruise's inside track, especially when he found out that Cruise (and Cruise alone) had a direct line to Miscavige's office.  And you don't even want to know what Travolta thought of the Church providing Cruise with a custom-built airplane hangar and custom motorbikes! It's just clear that the Church considers Cruise the top celebrity dog. And Travolta is livid!

But the absolute corker for Travolta is the fact that the Church did up a luxury penthouse for Cruise near its Headquarters in Clearwater Florida! Former security guard Brendan Tighe has said it was decorated to suit Tom's taste and he (and he alone) had special access to it. It seems that the penthouse is now Tom's main base of operations. That must make Travolta see red. Reportedly, Cruise's adopted son Connor lives nearby. He's beach bod by day and a D.J. by night.

RELATED: Everything We Know About Tom Cruise's Son, Connor

So, yes, it appears the feud between John Travolta and Tom Cruise is very, very real. From the 1970s, Travolta was top dog in the Church of Scientology, until the younger Tom Cruise came along in the 1980s. And according to sources like Brendan Tighe and Leah Remini, Travolta just cannot accept that Cruise is well and truly the top celebrity dog in the Church.

And in the future? Travolta's 20-something daughter Ella Bleu has become active in the Church, as have Cruise's adopted children with Nicole Kidman, Connor, and Isabella. So will the rivalry continue into the next generation? Almost certainly.

NEXT:  Everything We Know About John Travolta's Daughter, Ella Bleu