While the X-Men usually have their hands full on Earth fighting for their dream of peaceful mutant/human coexistence, they have also traveled to the stars a number of times and developed a long-standing relationship with the alien race of Shi'ar and the space pirate crew known as the Starjammers.
The Starjammers were created by writer/artist Dave Cockrum before they were worked into the X-Men's mythology. They developed their ongoing relationship with the mutant team before the space pirates starred in a few of their own limited series and featured in a number of important cosmic events that fans won't want to miss.
10 The Phoenix Saga
The Starjammers' first appearance in the comics coincided with the debut of Princess Lilandra Neramani, who would soon fall in love with Professor Xavier after she requested his assistance with her brother D'Ken, the mad Shi'ar emperor.
The Starjammers were assisting Lilandra, who arrived on Earth during the iconic Phoenix saga. The Starjammers would help the X-Men to save the universe from D'Ken and the M'Kraan Crystal, while the familial relationship between Cyclops and Starjammers' captain Corsair was discovered by the Phoenix, but not revealed.
9 Reunion
The actual revelation wouldn't come until the "Reunion" storyline that brought Corsair together with Cyclops and Storm as they battled the alien threat known as the Sidri. This storyline was partially adapted by the fan-favorite X-Men: The Animated Series episode "Orphan's End."
This storyline would lead to another space-adventure for the X-Men alongside the Starjammers as Lilandra's new rule was threatened by her exiled sister Deathbird. This would also introduce The Brood and debut Carol Danvers/Captain Marvel's Binary form prior to both her and Lilandra joining the Starjammers.
8 Phalkon Quest
Professor Xavier would also join the Starjammers for their two-issue appearance in X-Men Spotlight On... The Starjammers, which featured one of the largest and most powerful rosters of the team as they became rebel fighters alongside Lilandra.
The Starjammers raced against Deathbird and her forces to find the fabled map to a power source located on the mythical planet of Phalkon. The quest culminated in an action-packed finale full of guest stars like Excalibur and X-Factor.
7 The Avengers Vs. The Starjammers
Operation: Galactic Storm saw the Avengers get involved in the galactic war between the Shi'ar (under the rule of Deathbird) and the Kree which resulted in the death of their leader, the Supreme Intelligence, leading to Deathbird's takeover.
Members of the Starjammers picked up a bounty on the Avenger responsible for the killing stroke in Avengers #350. This brought the space pirates into a confrontation with Earth's Mightiest Heroes, increasing their presence in the greater Marvel universe.
6 The Troyjan War
During a period when the Hulk was working alongside an organization known as the Pantheon, he was forced into space to rescue one of his team. The Hulk was aided by his former Defenders teammate, the cosmically-powered Silver Surfer.
After a battle in Troyjan space left Hulk drifting and alone, he encountered the Starjammers by slamming into their windshield in a scene similar to Thor's first MCU meeting with the Guardians of the Galaxy. This led to a cosmic team-up between the pirates and the Defenders.
5 The Uncreated
The rebellious space pirates starred in their own Starjammers miniseries in the '90s that saw the once-again wanted team dealing with the threat of a new extremist alien species known as the Uncreated.
The powerful alien species began to eradicate every species they encountered that practiced a religion, which brought the highly devout Shi'ar into their crosshairs. The Starjammers are forced to work with their former allies turned enemies in the Shi'ar in order to deal with the Uncreated, but the strained relationships between them led to morally questionable decisions.
4 The Rise & Fall Of The Shi'ar Empire
Following the reveal of the revenge-fueled Gabriel Summers/Vulcan in X-Men: Deadly Genesis, a team of X-Men joined the Starjammers in space to try and stop Vulcan's schemes against the Shi'ar Empire while also revealing Vulcan's existence to his father Corsair.
The storyline that ran through the pages of Uncanny X-Men featured epic battles between Vulcan and pretty much everybody that involved the X-Men and the Imperial Guard. It shook up Marvel's cosmic characters while also dramatically changing the course of the Starjammers for the next few years.
3 Emperor Vulcan
The Starjammers found a new leader in Corsair's middle son, Alex Summers/Havok. His crew of remaining X-Men joined with the space pirates and Lilandra in multiple wars both against and with Vulcan's forces as opposing alien races became involved in the spreading galactic war.
Havok and the Starjammers continued to play a pivotal role in the following Kingbreaker series that saw Vulcan attempting to expand his galactic rule. This led to the War of Kings event that further cost the Starjammers in a continuing series of tragic events.
2 All-New Starjammers
After the time-displaced original X-Men were brought to space for "The Trial of Jean Grey" storyline, young Cyclops learned about his father Corsair for the first time. Consequently, he decided to travel with the Starjammers for some bonding time with his father during the solo Cyclops series.
This brought the pirates into the Black Vortex event alongside Nova and even Captain Marvel in a continuing series of crossovers between All-New X-Men and Guardians of the Galaxy. This occurred during the Brian Michael Bendis-era on both titles.
1 Poison X
The Starjammers were captured by a team of mercenaries who were hunting alien Klyntar symbiotes that they used to enhance themselves, leading to a team-up between X-Men Blue and Venom during the Poison X crossover event.
While the Starjmmares were imprisoned for a portion of the storyline, they would play a large role in the crossover as the X-Men gained new symbiotes that would lead to the Venomized event that closed out the Venomverse saga.