Their origins are shrouded in myth, making it difficult to nail down the truth of all of the stories written about them.
Reign of Ouranos
Ouranus now rule of Olympus mated with Gaea producing a number of powerful offspring: the Titans, the Cyclopes and centimanes. Ouranus feared his children would usurp his power so he imprisoned the centimanes and cyclopes in Tartarus, the dark abyss of the underworld. Gaea, disgusted with the treatment of her children urged the Titans to overthrow Ouranus. The youngest Chonus agreed and led his brothers into ambushing Ouranus in his sleep. He then castrated him with a sickle given to him by Gaea. A dying Ouranus prophesized that one of Cronus' own children when overthrow him just as he had overthrown Ouranus. Cronus then took his sister Rhea as his wife and became the new ruler of the Olympus.The dying Ouranos prophesied that Cronus would be overthrown by one of his own sons.
Reign of Cronus
Cronus seized Olympus, but he neglected to free the Cyclopes or the Hekatonkheires. His wife, Rhea, upon the birth of each of his own children, Cronus had the infant imprisoned in Tartarus. The offspring he sent there were Hades, Poseidon, Hera, Demeter, and Hestia. Appalled at the mistreatment of their children, Cronus's wife Rhea concealed her sixth pregnancy from him and secretly gave birth to Zeus and hid him on the island of Crete.
Zeus grew to adulthood among the shepherds of Mount Ida, Crete, and then set about taking revenge on Cronus. Zeus went down into Tartarus and freed his siblings, who had all now grown to adulthood, Zeus also freed the three one-eyed giants called Cyclopes and the three hundred-handed giants called Hekatonchieres, all six of whom Cronus had imprisoned there for fear they would help overthrow him. The Cyclopes provided the young Olympians powerful weapons to defeat the the gave Poseidon a powerful "Trident", Hades the Helm of Invisibility and gave Zeus the powerful "Thunderbolts". The young Olypmians and his allies fought a ten year war with the Titans which ended with Zeus's victory. 
Reign of Zeus
Following their final victory, the three brothers divided the world among themselves: Zeus was given Olympus, and was recognized as overlord. Poseidon was given the oceans of Earth, whereas Hades was given the Underworld, the realm of the dead. He was tasked with guarding the Titans for all eternity.
Zeus married the goddess Hera, but he engaged in many affairs with goddesses, titans, nymphs and mortal women and produced various famous offspring. By Hera, he sired Ares, Eris, Hebe and Hephaestus. His first lover was Metis, a Titan he sired Athena. A relationship with Dione, a Titan produced Aphodite. He was involved with Leto and sired the twins; Apollo and Artemis. He was also involved with Maia a Nymph and sired Hermes.
Some accounts depict them as being active as long ago as 20,000 BC. The Olympians, including at least Athena and Poseidon, were active and worshiped on Atlantis. Atlas supported the Axis Mundi was located in Atlantis.
For some reasons, Alexander of Macedon and his armies were briefly sent to the Hyborian Age, 10,000 years before their era, and the descendants of those who stayed there invoked "Zoos", a god unknown to Conan.
Around 8000 BC, at the end of the Hyborian Age beings known as the Olympians travelled from the interdimensional realm of Olympus via a nexus located on Mount Olympus to Earth. They began interacting with the humans of the region who began to worship them.
6th millennium BC
Mount Olympus lay near Olympia, the principal city of the Eternals. Zeus and his daughter Athena met with Zuras, the leader of the Eternals, and his daughter Azura. Noticing the physical resemblance between Zeus and Zuras and between Azura and herself, Athena suggested that the Olympian gods and the Eternals form an alliance in which the Eternals would act as the gods' representatives on Earth. The other three enthusiastically agreed, and Azura took her current name of Thena to signify the sealing of the pact. However, over the years, many humans came to think of many Eternals not as the gods' representatives but as the gods themselves. This led to a growing resentment by the gods towards the Eternals, which erupted into a brief war.
Between 1271 B.C. and 1268 B.C. Hercules was best known for his celebrated Twelve Labors, which were performed in part to prove his worthiness for immortality to Zeus.
In 1194, B.C., The Trojan War was a war between Greece (Greeks) and the City of Troy and its allies. The strife began after the Trojan prince Paris abducted Helen, wife of Menelaus of Sparta. When Menelaus demanded her return, the Trojans refused. Menelaus then persuaded his brother Agamemnon to lead an army against Troy. This lasted for many years.
Millenia ago there was a war between the Olympians and the Amatsu-Kami.Zeus and Amatsu-Miksaboshi separately told a single blacksmith to forge a weapon for them. The blacksmith crafted two swords: one perfect, the other flawed. The perfect was called Grasscutter Sword and the flawed one was called Godkiller Sword. The war went on for millennia with no clear winner.
Roman Empire (146 BC–324 AD)
1st century BC
When Christianity replaced the worship of the Olympian gods in the Roman Empire, Zeus decided that the time had come for the Olympians to break most of their ties with Earth. Poseidon, however, was still allowed to watch over his Atlanteans worshipers.
In 1000 AD, the Third Host of the Celestials occurred, during which the aliens informed they would return 1,000 years later to judge Earth's right to continue existing. Izanagi attended the Council of Godheads meeting to discuss this threat. While the pantheons prepared for war, Gaea planned a peaceful solution to the problem with many goddesses.
For the next thousand years, they searched for humans representing mankind's highest ideals, to be offered to the Celestials as an offering. The goddesses placed the candidates in suspended animation, with their superhuman potential, the legacy of the First Host, awakened.
On September 18th, 1793, the President of the United States of America, George Washington, was at a ceremony laying the corner stone of the capital of the new city Washington, D.C.. When he was laying the stone he looked into the sky and noticed something he had never noticed before, Atlas holding up the heavens thus revealing that the Axis Mundi was now in North America.
Zeus's children Hercules and Venus spent periods living among Earth mortals in recent years.
Assault on New Olympus
Ares: God of War
Taking advantage of the chaos left by the fall of Asgard and the Norse pantheon, Mikaboshi planned to extend his influence by capturing Olympus and crushing the Olympian gods. With the Olympians defeated, Mikaboshi hoped to compel all the other pantheons into surrendering. To this end, Mikaboshi laid siege to Olympus, which was very close to succeeding. Ares, still bitter about the treatment he received from the other Olympians, refused to raise a finger to help them. Desperate for his aid and wishing to goad Ares into action, Zeus had Alexander kidnapped and brought to Olympus where he was placed under the care of Achilles and his Myrmidons. With Mikaboshi in utter control of the battle, Hermes went to Earth to fetch an enraged Ares in an attempt to get him to speak with Zeus, but Ares' only concern was his son. Relenting, Hermes transported them both to Achilles' stronghold where they kept Alexander, only to find the fortress destroyed and Alexander missing. While Achilles was away, Mikaboshi's forces managed to destroy the Myrmidon fortress and steal Alexander away to his own stronghold in the eastern lands. Mikaboshi slowly began to warp Alexander's mind in an attempt to turn him against his father by revealing the brutal history and patricides committed by the Greek gods. Mikaboshi hoped to turn Alex into the new god of war, one that could be used against the Greek gods and, more importantly, Ares himself. Finding out his son was in the hands of Olympus' enemies, a furious Ares begrudgingly agreed to join in the fighting, but only to rescue his son. During the battle, Zeus was on the brink of death and used his remaining power to break the hold Mikaboshi had over Alexander. Alexander used the grasscutter sword against Mikaboshi and ended the battle. Mikaboshi was then returned to the Japanese land of the dead defeated.
Athena of the Olympian Pantheon called a meeting of the Pantheons in San Francisco to assemble a team of gods from Earth, known as the "God Squad". Mikaboshi was chosen by the pantheons of the east along with Hercules, Snowbird, Tecumotzin, and Atum, the God Eater to battle and defeat the Skrull Gods Kly'Bn and Sl'gur't. In route to Skrull space through the dream realm, they battled Nightmare. Mikaboshi was key in winning the battle by being able to make duplicates of himself. Upon arriving in Skrull space, the God Squad had to battle their way through conquered pantheons of gods on the way to Kly'Bn and Sl'Gurt’s thrones. Mikaboshi attacked Sl'gur't after she destroyed Atum, and both took shape of the same creatures during battle, eventually taking the form of each other. Mikaboshi killed Sl'gur't before being left by Hercules, Snowbird, and Amadeus Cho who thought Mikaboshi was killed, thus leaving Mikaboshi to take command of the conquered pantheons.
The Olympus Group was founded sometime in the 20th century by Zeus. Its original purpose is unknown, but since the desolation of Olympus by the undead forces of Amatsu-Mikaboshi, it has formed the base of the Olympians power on Earth.
The first sign of the Olympus group's new direction came when Hera assumed control upon the death of Zeus. Combining his shares in the company with hers, she allied with Typhon, the Volcano Titan, and forced out Poseidon.
During the Dark Reign, the Olympus Group was working towards "Continuum©", the ultimate goal of which was to replace the Earth with a new, better version, leaving behind all the baggage the world had created and ending the "Iron Age" of classical Greek mythology. Continuum© was opposed by Hercules and his allies, the Avengers, at the cost of Hercules' life.
The Heroic Age
In the wake of Continuum©, Athena took control of the Olympians and returned them to Olympus. Control of the Olympus Group devolved to Amadeus Cho, ally of Hercules, who had been selected as the "Prince of Power" for the new age.
The Olympus Group was strengthened by adding the assets of the late Hercules to their portfolio. . Said stock includes but is not limited to: multiple wineries and breweries, a nude beach resort, an adult entertainment shop and a significant share in Stark Enterprises.
- ↑ Thor Annual #5
- ↑ 2.0 2.1 Thor & Hercules: Encyclopaedia Mythologica #1
- ↑ 3.0 3.1 3.2 Incredible Hercules #130
- ↑ 4.0 4.1 4.2 Incredible Hercules #123
- ↑ 5.0 5.1 Incredible Hercules #127
- ↑ Official Handbook of the Marvel Universe A-Z #8
- ↑ Thor: Asgard's Avenger #1; Artemis' entry
- ↑ Captain America Comics #3
- ↑ Official Handbook of the Marvel Universe A-Z Update #2; Gorgons' entry
- ↑ Conan the Barbarian #79
- ↑ Conan the Barbarian #80
- ↑ Marvel Atlas #1
- ↑ Namor the Sub-Mariner #38
- ↑ Incredible Hercules #116
- ↑ Incredible Hercules #117
- ↑ Incredible Hercules #113
- ↑ Thor Annual #8
- ↑ Marvel Illustrated: The Odyssey #1-8
- ↑ Young Allies #16
- ↑ 20.0 20.1 Official Handbook of the Marvel Universe A-Z Update #1; Atlas' entry
- ↑ Secret Warriors #10
- ↑ Official Handbook of the Marvel Universe #8
- ↑ Tales to Astonish #75
- ↑ Thor Annual #7
- ↑ Official Handbook of the Marvel Universe A-Z Update #1; Young Gods' entry
- ↑ Incredible Hercules #124
- ↑ Ares #2
- ↑ Ares #3
- ↑ Ares #5
- ↑ Incredible Hercules #118
- ↑ Incredible Hercules #120
- ↑ Hercules Vol 3 #3-5
- ↑ Assault on New Olympus #1
- ↑ Heroic Age: Prince of Power #1
- ↑ Hercules: Fall of An Avenger #1
- ↑ Hercules: Fall of An Avenger #2