The relationship between Wolverine and Deadpool in the movies is well-known, dating back to Deadpool's disastrous debut in Wolverine's debut solo feature. However, the way their relationship was portrayed in that film left many dissatisfied, including the actors themselves.

We have every expectation in the world that Marvel Studios would draw from the untold comic book history between Wade Wilson and Logan, though, since Deadpool and Wolverine are luring Hugh Jackman out of retirement to give the Merc With a Mouth and the Best There Is the tandem adventure they deserve. 

As roughly depicted in the previously stated film X-MEN Origins: Wolverine, Wolverine and Deadpool have a long history in comic books, mainly through the Weapon X program. However, there is much more to their relationship and even their Weapon X links than you may believe.

As previously mentioned, the primary link between Deadpool and Wolverine is from the Weapon X program, an experimental initiative undertaken by the US and Canadian governments to produce super-soldiers and living weapons that would serve as spies, warriors, and superheroes for their respective nations.

Weapon X, which is a part of a bigger program called Weapon Plus that dates back to WWII and the transformation of Steve Rogers into a super-soldier, experimented on both Deadpool and Wolverine.

Wolverine's involvement in Weapon X predates Deadpool's, with Weapon X being responsible for injecting Adamantium into Wolverine's bones, and for wiping and scrambling his mind, leading to the long-running mysteries about his true past and identity.

Back in Deadpool/Death Annual '98, an issue where Deadpool teams up with Marvel's corporeal manifestation of Death (which we rated one of the best Deadpool storylines of all time), that peculiar secret was finally disclosed. But rather than being a retcon, the relationship between Deadpool and Wolverine was intended from the beginning by artist Rob Liefeld. Liefeld has said in the past that Deadpool's involvement with the Weapon X program was pre-programmed from the time he debuted in New Mutants #98 in 1991. Indeed, Deadpool's past has sowed the seeds of those ties. In the poorly regarded 2009 movie X-MEN Origins: Wolverine, where Ryan Reynolds played the fast-talking Wade Wilson, some of this history was on show.

Despite not being a mutant, Deadpool has frequently been linked to mutants and mutant teams because of his affiliations with the Weapon X program and other ideas and figures from the X-MEN canon. Together with Wolverine, he was a member of the ferocious, deadly black-ops unit X-FORCE, another X-MEN team. Deadpool's origins with X-Force date back to New Mutants, the comic book series that immediately followed Deadpool's debut in the Marvel Universe and eventually became X-Force. Deadpool shares a lengthy relationship with the mysterious mutant Cable, who led the original X-Force, a paramilitary group that split off from the X-Men. However, the X-FORCE moniker was eventually brought back to life when the X-MEN squad faced the mutants.

The experiments that turned Wade Wilson into DEADPOOL  were partially based on WOLVERINE'S mutant physiology, with Wolverine's own mutant healing factor providing the genetic basis for Deadpool's artificial healing factor.