The universe was formed in a massive explosion known as the Big Bang. In the aftermath of the explosion, matter and energy gradually condensed into the universe we know today.

The Guardian of Forever was a time portal created billions of years ago. It remains functional until at least the 23rd century, and it may be the last surviving artifact of an incredibly ancient civilization, although its origin and purpose are still a total mystery.

The star that would one day be known as Sol began to condense out of nebular material, forming the sun and our solar system.

The civilization on planet Tagus III flourished two billion years ago. By the 24th century, much still remains a mystery about this ancient race, at least partially because the ruins on the planet have been sealed off since Earth's 23rd century. Nevertheless, Tagus remains a subject of interest to many archaeologists and enthusiasts, including Captain Jean-Luc Picard.

First single-celled organisms evolved on Earth

The inhabitants of planet Organia underwent a transformation from humanoid bodies to beings of pure energy.

The Tkon Empire became extinct about 600,000 years ago when their sun went supernova during a period of time known to the Tkons as the Age of Makto. According to legend, the Tkons were once enormously powerful, even capable of moving stars. Prior to the Age of Makto, other Tkon eras included the Ages of Fendor, Ozari, Xora, Cimi, and Bastu. The population of the Tkon had numbered in the trillions.

Sargon's people, a technologically advanced civilization, explored the galaxy aboard space vessels ad planted colonies on many planets. Spock speculated that Sargon's account of such colonization might explain certain elements of Vulcan prehistory, suggesting that Spock's people may have originally been from Sargon's planet.

Civilization flourished on the planet Bajor many millennia ago. The culture boasted architects, artists, builders, and philosophers. By Earth's 24th century, the Bajoran culture was all but destroyed by the Cardassians, who forced the Bajorans to resettle on neighboring planets.

The star Exo, which had at one time been bright enough to support life on its planet Exo III, began to fade about 500,000 years ago, eventually rendering the planet's surface uninhabitable, with temperatures of 100 degrees below zero. Dr. Roger Korby's research discovered that as the sun dimmed, the civilization moved underground for survival, becoming more mechanized and less human. The android Ruk had been built by the ancient civilization that he called "the Old Ones." At the time of Korby's arrival on Exo III, Ruk had been tending the Old Ones' machinery for many centuries. Androids had apparently been commonplace in the now-vanished culture, but at some point the Old Ones began to fear their creations, and tried to deactivate them. The androids eventually learned to defend themselves, resulting in the deaths of the Old Ones.

A terrible cataclysm on Sargon's planet totally ripped the atmosphere away about 500,000 years ago. The planet was left almost totally dead, the only survivors suspended in special protected canisters stored deep below the surface. Millennia later, Sagon would describe the cataclysm as being the result of a crisis faced when a civilization becomes so powerful its inhabitants dare think of themselves as "gods." Prior to this disaster, Sargon's people roamed the galaxy aboard starships.

The technologically advanced inhabitants of planet Talos IV were nearly wiped out by a terrible war thousands of centuries ago. The war made the surface of the planet uninhabitable, and the few remaining Talosians survived by living underground. They found this life limiting, so they devoted themselves to developing their mental powers, while their technical skills atrophied. They developed a practice of telepathically sharing illusory experiences with specimens in their menagerie of alien life-forms, gathered prior to the war, when Talosians were a space faring race. The Talosians eventually found such illusions to be dangerous narcotic that very nearly destroyed what was left of their civilization.

The civilization of the planet Iconia flourished many millennia ago, becoming a strong influence on many ancient cultures, as evidenced by linguistic similarities between Iconian, Dewan, Iccobar, and Dinasian. Ancient texts described the Iconians as "demons of air and darkness," suggesting the Iconians could travel to other planets without the use of spaceships, possibly with the use of an interdimensional transport system. The Iconian civilization was evidently destroyed some 200,000 years ago when all major cities on Iconia were heavily damaged by large-scale orbital bombardment.

The Horta of planet Janus VI began their most recent cycle of rebirth about 50,000 years ago. At that time, their entire race died, except for one individual who guarded their Vault of Tomorrow which contained the eggs for the next generation of Horta. This individual became the "mother" of her race.

Lokai of the planet Cheron attempted to lead a revolution against that planet's government, fighting against what he saw as racial injustice and oppression of his people. Although the Cheron government claimed to have been making reforms, these were deemed inadequate by Lokai and his followers. Lokai was convicted of treason, but managed to flee from the planet. He was followed by Commissioner Bele on a pursuit that would last some 50,000 years, ending only after racial hatred had destroyed their entire civilization.

Two unknown adversaries outside of our galaxy fought a terrible war, culminating in the use of a "doomsday machine." Intended as a bluff, the device was so powerful, it would destroy both sides. Unfortunately, the planet-killing weapon apparently did exactly that, and subsequently wandered intergalactic space for unknown millennia before attacking at least six solar systems near L-374 in our own galaxy.

The first of at least 947 archaeological expeditions was conducted at the ancient ruins on planet Tagus III, about 22,000 years ago. Among these studies were a number of Vulcan expeditions that concentrated on the northeastern part of the city.

The Trill began living as a "joined species," a pairing of intelligent but helpless creatures who live in humanoid host bodies. So complete is the symbiotic relationship that most outside observers deal with the joined Trill as single entities.

The machine-god Vaal on planet Gamma Trianguli VI was built at least 10,000 years ago in order to protect the inhabitants of that planet by providing food and climate control.

A race of intelligent spacefaring organisms became nearly extinct some millennia ago. These organisms formed symbiotic relationships with humanoid life-forms that lived within their bodies, providing life support, and effectively becoming "living spaceships" to their humanoid companions. The last surviving specimen, an individual that called itself Gomtuu (and would eventually be known as Tin Man to the Federation), suffered injury when radiation from an explosion penetrated it's outer layers, killing it's crew. Gomtuu wandered alone through space for millennia, looking unsuccessfully for others of it's kind, eventually becoming despondent because it was dependent on it's humanoid crew for emotional sustenance.

The sun of the Fabrini system went nova about 10,000 years ago, destroying the planets in that system. Before this happened, the inhabitants of the planet Fabrina created a giant space ark to insure the survival of their species. The ark, fashioned from a 200-mile-diameter asteroid, was known as Yonada to it's inhabitants, and was designed to simulate perfectly the surface of their home world for a ten-millennium voyage to a planet near Darin V.

The Kalandans constructed a small planet, about the size of Earth's moon, for colonization. Despite the planet's small size, it had a Class-M environment and supported a Kalandan outpost until a deadly disease organism, accidently created in the planet's formation, killed all the inhabitants. This left the automated defense systems to protect the now-vacant outpost.

The great leader Landru of planet Beta III in star system C-111 chose to provide for his people's future after his death by creating a powerful computer system that would run the planet's society. Prior to Landru's rise to power, the planet had been wracked by war. Landru changed his society, returning to a simple time of peace and tranquility. The computer, which was made operational about 6,000 years ago, was programmed with the sum of Landru's knowledge was given the prime directive of always acting for the good of the people. The knowledge that Landru had been replaced after his death with a computer was kept from the people.

Unknown aliens took several hundred humans from Earth to be raised on a distant planet some 6,000 years ago. The descendants of these humans were trained for generations so that they could be secretly be returned to Earth as part of an effort to prevent Earth from destroying itself before it could mature into a peaceful society.

An Ice age began on planet Sigma Draconis VI, triggering a remarkable regression in the civilization there. Once technologically advanced beyond the Federation 23rd-century level, the society regressed to a virtual Stone Age. Although some elements of their past technological achievements remained, the inhabitants no longer possessed any understanding of the technology in the 23rd century.

Planet Earth was visited by a group of aliens who settled the Mediterranean area some five thousand years ago. The aliens, who possessed powerful psychokinetic abilities, were worshiped by the ancient Greeks as gods and were apparently the origin of many Greek myths. The humans eventually outgrew the cultural need for these gods, who departed Earth for planet Pollux IV. Many years later, the last alien - who was known as the god Apollo - attempted to persuade members of the Enterprise crew to worship him as did the ancient Greeks.

Planet Sarpeidon experienced an ice age some 5,000 years ago. A woman from Sarpeidon's present, Zarabeth, was exiled into this path by the tyrant Zor Khan, after two of Zarabeth's kinsmen conspired to kill the dictator. Zarabeth lived completely alone in this past, except for a brief visit from Spock and McCoy, who accidently traveled into the past thorough Sarpeidon's Atavachron time portal.

4,000-3,000 B.C. First large-scale human civilizations developed in Sumer region of the Nile river valley on Earth. The Sumerians were responsible for the earliest known form of writing, known as cuneiform. The civilization also had the first known records of the use of wheeled vehicles. The first epic tales of Gilgamesh began in this period.

The progenitors of planet Aldea in the Epsilon Mynos star system install a powerful cloaking shield around their planet, controlled by a sophisticated computer called the Custodian. The Aldeans, who sought anonymity to avoid marauders and other hostile passerby, eventually faded into mythology untill the cloaking shield began to cause major environmental damage on Aldea, forcing the Aldeans to seek outside help in 2364.

3834 B.C. The (nearly) immortal Flint was born in Mesopotomia on Earth. Flint described his early self as a bully who didn't die, despite serious injuries in an ancient war. Flint lived under a variety of assumed names, including Merlin, Leonardo da Vinci, and Johannes Brahms, finally settling on a small planet he purchased under the name of Mr. Brack.

The star known as Sahndara went nova, presumably destroying the planets in that system over 2,500 years ago. At least a few of the natives of one of the planets were able to escape. They spent some time on planet Earth, circa 400 B.C., where their leader, Parmen, became a great admirer of the philosopher Plato. After leaving Earth, circa 200 B.C., they settled on a planet they named Platonius, and attempted to pattern their world after Plato's Republic. About six months after their arrival on this planet, the Platonians began to develop powerful telekinetic abilities, the result of having absorbed trace quantities of kironide from the planet's environment.

500-600 B.C. First records of parts of the Old Testament. Birth of Confucianism and Buddhism. Height of the Greek age of philosophy and the influence of the Greek oracle at Delphi.

Spock's ancestors adopted a ceremonial ground that remains in their family at least until the 23rd century. These ceremonial grounds, used for the mating ritual, embody the Vulcan heart and soul, reflecting Vulcan culture from the "time of the beginning."

4 B.C. Jesus Christ was born. Christ's teachings would become the basis of Earth's Christian religion.

The inhabitants of planet Vulcan were engaged in terrible and destructive wars, a result of the passions and emotions that governed the Vulcan people. Spock described this period as savage, even by Earth's standards. The great philosopher Surak led the Vulcan people on the path toward logic and peace, demonstrating enormous courage working for peace in the face of war. This may also have been the event that triggered the departure of Vulcan dissidents who left their home planet to found what eventually became the Romulan Star Empire.

The society on planet 892-IV, evolving on a path similar to that of Earth, developed a culture similar to Earth's ancient Rome, a remarkable example of Hodgkin's Law of parallel planet development.

A terrible war broke out on planet Solais V some 1,500 years ago. The conflict lasts into the 24th century, at which time the historic enemies are on a verge of extinction.

The people of planet Kaelon II adopted the custom of the Resolution, a ceremony in which individuals commit suicide at the age of 60 to avoid being a burden to their society. This practice, still observed in the 24th century, is considered to be a celebration of life, allowing it to end in dignity.

An individual of the Metron civilization was born about 1,500 years ago. In the year 2266, this individual was responsible for his race incapacitating the Starship Enterprise and a Gorn space vehicle, attempting to end a conflict between the two by allowing the commanders of the two spacecraft to engage in physical combat. Little else is known of the Metrons, as they have chosen to remain undetectable to Federation science.

The technologically advanced civilization on planet Vantax II was suffering from overcrowding, environmental pollution, and terrible wars a thousand years ago. The Ventaxians, according to historical record, entered into a pact with a supernatural being called Ardra. The agreement called for Ardra to grant the planet a millennium of peace and prosperity. At the end of this span, Ardra would be entitled to claim the planet and it's inhabitants.

Nearly all life on the planet Zetar was destroyed about a thousand years ago by some terrible cataclysm. Only a hundred individuals from that planet survived in the form of energy patterns representing their thoughts and their will. These individuals searched for a millennium to find a suitable physical body through which they could live.

Promellions and Menthans fought a devastating war near planet Orelious IX at least 1,000 years ago. The war was so fierce that it resulted in the destruction of the planet as well as both cultures. Space near the former Orelious IX is now occupied by and asteroid field, the remains of the planet.

The planet Kataan in the Silarian sector experienced a severe drought, found by the planet's inhabitants to be due to a gradual increase in solar radiation. Over a number of years the increase culminated in the star going nova, destroying all life in the system. Prior to the explosion, the Kataans were successful in launching a space probe containing a memory record of life on that planet. The probe travels for a thousand years before encountering the Starship Enterprise commanded by Captain Picard.

The inhabitants of the planet Thasus once had corporeal bodies of solid matter, but have long since evolved into forms of pure energy.

The ruling family of the Ramatis star system was discovered centuries ago to lack the gene required for the sense of hearing. Asystem was developed whereby a "chorus" of interpreters both hear and speak for the members of the ruling family. This ingenious arrangement continued for centuries, with each succeeding generation of chorus family members continuing to provide services to the ruling family members.

The people of planet Ardana built a magnificent city in the clouds. The city, named Stratos, was built centuries ago and was described as the finest example of sustained antigravity elevation in the galaxy. The leaders of the cloud city promised the people of Ardana that all would be able to live in Startos, but after construction was completed, the members of the working class were not allowed to live there.

A.D. 625 Mohammed began writing the Koran. This work would become the cornerstone of the Muslim religion.

A civil war began centuries ago on planet Daled IV. The planet, which rotates only once per year, has one hemisphere in perpetual light and the other in eternal darkness. As a result, two disparate civilization had evolved on the world, so different that they fought for many centuries. A young woman, whose parents each came from a different side, is later raised on a neutral planet in the hope that she can bring peace to her world.

A.D. 1609. Galileo Galilei constructed Earth's first astronomical telescope. Galileo would later become known as the father of modern science for his work supporting the Copernican view of the universe.

A group of alien interstellar anthropologists called the Preservers visited planet Earth at least several hundred years ago. They judged Earth's American Indians to be in danger of extinction, and transplanted them a small group of Delaware, Navajo, and Mohicans to a distant Class-M planet, where they were encouraged to live in a manner that preserved their culture. Since this planet was near a potentially dangerous asteroid belt, the Preservers provided a powerful deflector beam mechanism to protect the settlement from asteroid impacts. The transplanted Indians refer to their alien benefactors as The Wise Ones.

Archeological research cited by Spock indicates the Beta Portolan system was overcome by mass insanity in the distant past. This was apparently the same affliction that struck planet Deneva in 2267, killing many colonists, including Kirk's brother and sister-in-law. Spock suggested that Beta Portolan was the original source of the insanity that also affected planets Lavinius in 2067 and Ingraham B in 2265.

The two inhabited planets of the Eminar star system began a bitter war. The planets, known as Eminiar VII and Vendikar, were in danger of destroying each other, when an agreement was reached in which the war would be conducted by computer simulations, with the computers determining casualties on each side. Once casualties were calculated, the appropriate individuals would report to disintegration chambers so their deaths would be recorded. Representatives of Eminiar VII defended the arrangement as one that permitted both societies to survive despite a devastating war. The computer war lasted some 500 years, until the intervention of Captain Kirk in 2267 broke the radio link between the two planets.

Colonists from planet Peliar Zel migrated to that world's two moons. Relations between the two off world colonies were strained at best, and Peliar Zel Governor Leka would later describe them as "two squabbling children." Hostilities extend into the 24th century, when the services of Trill ambassador Odan are instrumental in maintaining peace in the system.

Hundreds of condemned criminals from a star system called Ux-Mal were imprisoned on a moon of the planet Mab-Bu VI. The criminals were somehow separated from their bodies and their life entities were left to drift in the electromagnetic storms in the moons atmosphere.

1893. Lieutenant Commander Data is accidentally thrown back into the past while investigating evidence that aliens from the future may have attempted to interfere with Earth's history. While in the 19th-century San Francisco, Data encountered writer Samuel Clemens, who became suspicious of Data's activities. Data also met Guinian in the past, learning that the future Enterprise bartender had visited Earth some 472 years prior to her service aboard the starship.