While X-Force has been re-introduced in the "Dawn of X" era as Krakoa's security forces, the team has a rich and complex history that has evolved over the years from the New Mutants' next step to a covert ops team tasked with taking out threats to mutantkind, so it may be difficult for new fans to get a full grasp on the team without doing some essential reading first.
There were a few teams that formed prior to the "Dawn of X" relaunch that used the name of X-Force, though they didn't add much to the team's overall legacy (Psylocke's team in the second volume of Uncanny X-Force or Cable's final outing with X-Force prior to his death in X-Termination), so focusing on the more essential storylines will help bring any new fan up to speed.
10 New Mutants
The first team of X-Force was formed out of the ashes of Professor Xavier's second class of X-Men known as the New Mutants, who had grown disillusioned during their time with the X-Men and were looking for a different path.
When the militaristic mutant known as Cable first arrived in New Mutants #87, he gathered young mutants like Cannonball, Boom-Boom, Warpath, Feral, Shatterstar and Domino into his own strike team, which signaled the end of the long-running series and the beginning of the best-selling X-Force.
9 Cable Vs. Stryfe
While X-Force found their footing as Cable's operatives, they frequently found themselves facing off with the Mutant Liberation Front, which was initially led by the mysterious mutant known as Stryfe, who would later be revealed as Cable's clone.
This storyline would lead to the "X-Cutioner's Song" event, which brought X-Force (now with Rictor, Siryn, and Sunspot as well) back into contact with their former allies while Cable was taken off the board, though his familial connection to Cyclops and Jean Grey was further teased as his team began to move on without their leader.
8 Back At The Mansion
Following the reality-altering Age of Apocalypse event and the destruction of the team's headquarters, Professor Xavier and Cable decided to begin working together again and X-Force was relocated back to the mansion.
The team received new matching costumes and rededicated themselves to Xavier's dream of mutant and human harmony, though they lost a long-time member as Cannonball graduated to the big leagues and joined the X-Men. This version of X-Force would later become involved in events like the Onslaught saga and Operation: Zero Tolerance.
7 Hitting The Road
After Bastion's Sentinels had taken over the mansion during Operation Zero Tolerance, Cable suggested that X-Force move underground, take on new identities and ride out the storm, but the majority of X-Force rebelled.
Dani Moonstar, Siryn, Warpath, Sunspot, and Meltdown (formerly Boom-Boom) struck out on their own and decided to head across America to find their own path yet again, after years of following others. While X-Force didn't get involved in too many big events or crossovers during this time, they were able to spend some time discovering themselves.
6 San Francisco
After some time on the road, the team decided to settle in San Francisco (long before the X-Men set up Utopia there) after Sunspot regained control of his family fortune, and they established a new warehouse headquarters.
Cannonball and Domino would rejoin X-Force and the team would begin to move forward as their own independent mutant squad alongside new member Bedlam, and the team would remain in San Francisco until they were again reorganized by Pete Wisdom during the Counter-X rebranding and the team's eventual disbandment.
5 Messiah Complex
While the "Messiah Complex" storyline was X-Men focused and occurred at a time when X-Force had been disbanded and the members had moved on to other teams or organizations like X-Corp, it featured the debut of a new era of X-Force.
After the first mutant birth since House of M had been kidnapped by Cable, Cyclops hand-picked his own team of hunters that included Wolverine, Wolfsbane, Hepzibah, X-23 and former X-Force members Warpath and Caliban to find Cable and rescue the baby, who was also being tracked by anti-mutant groups and Mister Sinister's forces.
4 Angels and Demons
Cyclops decided that the X-Men reacting to new situations wasn't going to keep them safe, so he reformed his X-Force squad under the control of Wolverine in order to covertly hunt down and take out possible threats to mutantkind.
This team included X-23, Warpath, and Wolfsbane from the original hunters' group and added members like Domino, Archangel, Vanisher and Elixir to the squad, though Cyclops would eventually disband the group after the "Second Coming" storyline revealed the team's existence to the rest of the X-Men.
3 The Apocalypse Solution
However, Wolverine believed in what his team was doing so he assembled his own team in Uncanny X-Force, which included Psylocke, Archangel, Deadpool, and Fantomex, who made the eternal mutant Apocalypse their first mission.
Unfortunately, the team encountered a youthful clone of Apocalypse that caused a moral dilemma for the team who were hoping to stop the rise of En Sabah Nur, though the team would ultimately be responsible for the death (and later rebirth) of the young mutant who would go on to become Genesis.
2 Dark Angel Saga
The members of Uncanny X-Force weren't always the most stable, as Warren Worthington III/Angel was beginning to lose his fight against the dark influences of his Archangel persona that was implanted by Apocalypse.
The "Dark Angel Saga" features Worthington's dark turn as he is overtaken by the Dark Angel and becomes Apocalypse's heir apparent as he attempts to eradicate the life on the world and restart evolution in his image, though he was defeated by the return of the young Genesis and Psylocke, who killed Archangel to save the world.
1 Final Execution
Rick Remender's Uncanny X-Men epic wrapped up with a final attack from Wolverine's son Daken and his newly assembled Brotherhood of Mutants, which included Mystique, Sabretooth, AoA's Blob, the Skinless Man, Shadow King and the cloned Omega Clan.
This assembled team of mutants gathered to take out Wolverine's team as revenge and even managed to kill Fantomex, though it was the Brotherhood who would ultimately lose as the majority were taken out by X-Force, which disbanded shortly after dealing with the final refugees from the AoA reality.