The four horseman are Apocalypse's personal warriors and always play a key role in his plans for mutant conquest and domination. The enhancements made to horseman are often a combination of both biological or genetic manipulation and the employment of the celestial technology that Apocalypse uses.

The use of the four horseman specifically is largely symbolic, and their powers are often either directly or closely related to their namesake. When mutants (or in some cases humans) that are to become horseman are chosen that do not have desired powers, Apocalypse will augment their powers to more closely resemble their role or give them new powers entirely. Regardless, the powers and abilities of a horseman are generally augmented or enhanced to serve Apocalypse's purposes.

Apocalypse is also known to brainwash reluctant horseman to become more obedient soldiers. Several horseman have been able to overcome Apocalypse's programming by sheer force of will. While brainwashing can be overcome, the transformation process can still be psychologically damaging and can haunt former horseman long after leaving Apocalypse's servitude.

Lastly, as a side effect of the transformation process a horseman's appearance will often change. This can be because of more obvious changes such as Archangel's metal wings, skin and hair color changes such as in Gambit and Angel as death, or other physical changes such as the enlarged stature and mass of Gazer as war.

The First Horsemen

The first four Horsemen Apocalypse ever recruited were Plague who he recruited during the mutant massacre as Pestilence. The second was Abraham Kieros who was War. Autumn Rolfson was his 3rd recruit he became Famine and the last one of the first Horsemen was the de-winged Angel who became Death (the Achangel) who was given razor sharp Metal wings and Blue skin.

The 4 horsemen fought each other to see who would be their leader Death(Archangel) won. Soon afterwards they fought X-Factor which they nearly lost till Death appeared. Caliban came to Apocalypse to get more power to avenge the Morlocks, who were killed during the Mutant Massacre. Since Pestilence (Plague) was killed and Archangel came back to his sense after he believed he killed Iceman, Caliban became the new Death.

Caliban captured Jean Grey and Cyclops under orders of Mr. Sinister. The X-Men came to the rescue and defeated Famine, Caliban, and Abraham Kieros (War). The X-Men were then later defeated by Apocalypse.

The Hulk

In a Battle with the X-men, The Hulk was defeated, found by Apocalypse, and made into the new War. To test his strength he was pitted against the Juggernaut, whom he pushed back. He also defeated Absorbing Man. He then came to his sense after injuring Rick Jones.

New Horsemen

Feeling that his leadership was more in need after the M-Day than ever before, Apocalypse emerged once again to lead the remaining mutant population against the human majority. In a move which could have been motivated by Apocalypse's narcissistic use of symbolism, the majority of the mutants that he selected for his next team of Horseman were de-powered on M-Day. The first Horseman Apocalypse recruited for his new team was Gazer, a mutant who was a part of a NASA research program, whose loss of power on M-Day left him dying of radiation poisoning. Gazer was pitted against a human archaeologist in a fight to the death to determine which would earn the first position of War. Unbeknownst to Apocalypse, Ozymandias the scribe of Apocalypse allowed Gazer to survive so that Gazer would owe him a life debt he planned to collect when he decided to turn on Apocalypse.

The next Horseman selected was the mutant Sunfire, who had lost his legs in a fight with Lady Deathstrike. Sunfire had allowed Rogue to take the remainder of his powers in order to finish the fight and defeat Lady Deathstrike. Powerless and crippled, Sunfire was approached by Apocalypse who offered him his legs, power, and dignity in exchange for servitude as Famine. Sunfire was brought to Apocalypse's temple, where he tried to help Gazer escape. When Sunfire was finally able to get to Gazer it was far too late, as Gazer had been transformed into War in both body and mind.

Polaris had lost her powers on M-Day, and had ventured out into the world in an attempt to discover how to become whole once more. The alien Doop led Lorina to Apocalypse's temple where she would be given back her magnetic abilities, as well as the ability to carry and transmit some of the most lethal diseases known to man, as the horseman Pestilence.

Finally, overcome by feelings of loss and self-loathing, Gambit sought out Apocalypse to volunteer himself as one of the Horsemen. Gambit was given the ability to remotely transmute gases into poison. His skin was also turned black to reflect his new role as Death.

When Ozymandias called upon Gazer to fulfill his portion of their arrangement, Gazer refused to turn on his master. Upon refusing, Ozymandias ran Gazer through with his sword right in front of Apocalypse. Gazer had also lead the X-Men into Apocalypse's temple, where they found Polaris. They took her back to the X-Mansion to receive heal from her transformation. Sunfire and Gambit were seemingly able to break free from Apocalypse's control and fled together, knowing that only each other would understand what they went through.

Present

Gazer is now dead. Lorna is back with the X-Men, and has been healed from her exposure to all of the diseases she encountered as Pestilence. She is adjusting to the magnetic powers that Apocalypse restored in her. Her powers are currently unwieldy and difficult to control, and seem to be technologically based now, rather than biologically. It is unknown where Gambit and Sunfire went after the battle with their allies, however they were recently approached by Mister Sinister.

Alternate Realities

Earth-295

In the Age of Apocalypse reality the horsemen were: Sinister, Holocaust Mikhail Rasputin and Abyss.

Earth-5701

In this reality the horsemen were: Archangel (Death), Spider-Man (Pestilence), Cable (War) and Blob (Famine).

Earth-1610

In this reality, only Mr. Sinister was the only horseman to be mentioned.

Earth-1298

Angel is the horsemen of death. He has bat-like wing, he could breathe fire and change his name to "the Fallen". He aligned himself with Havok and his team "the Six", but returned to Apocalypse's side to battle an evil Professor X.

Earth-1100

On one of the Exiles's missions, they encountered a version of Thunderbird as the horseman of War. he managed to overpower Apocalypse's influence in him and came back to his old allied, the X-Men.

Earth-58163

In the House of M, only Iceman was mentioned as a horseman but it is unknown what title he held. He was sent by Apocalypse to attack the country of Wakanda to kill Black Panther.

Earth-2301

In the Marvel Mangaverse, the horsemen is composed of Archangel, Juggernaut, Mister Sinister and Emma Frost.