Distant past

16 billion years ago

 * The universe is formed in the instantaneous expansion that scientists call the "Big Bang". The "Big Bang" has been theorized to be caused by destabilizing Omega molecules.
 * This point in time represents a hideout for members of the Q Continuum. The USS Voyager was briefly transported here by Quinn in order to escape Q, but he too had once used this hideout and was thus able to find the ship.

9 billion years ago

 * Hundreds of protostars collapsed in close proximity to one another forming the astronomical phenomenon later known as a black cluster.

7 billion years ago

 * The Theta 116 system begins the process of becoming a planetary system.

5 billion years ago

 * The star Sol begins to form out of nebular dust and interstellar gases.
 * Female Q is born.

4.5 billion years ago

 * The Guardian of Forever had been asked its last question (until 2267, when it told Captain James T. Kirk and Spock it had awaited a question "since before your Sun burned hot in space").
 * The star Sol takes form.
 * The ancient humanoids, one of the oldest known sentient species, seeded the oceans of many worlds with DNA codes, directing the evolution of life towards a physical pattern similar to their own. The varieties of lifeforms that carried this seed code to fruition include the Humans, Vulcans, Klingons and Cardassians, and likely many other humanoid species of the galaxy.

4 billion years ago

 * Q and Q begin their romantic involvement around this time.
 * The planet Pollux IV forms in the Beta Geminorum system.

3.5 billion years ago

 * On Earth, in a region later known as France, amino acids combine to form the first proteins.

2 billion years ago

 * Civilization thrives on planet Tagus III.

1 billion years ago

 * The Slaver Empire is the master of all intelligent beings in the Milky Way Galaxy. The Slavers and all of their subjects were exterminated in a massive war which caused all intelligent life to re-evolve.

400 million years ago

 * In the Permian period, Eryops, the last common ancestor of cold-blooded and warm-blooded organisms, lives on Earth.

300 million years ago

 * An alien ship of unknown beings is invaded by a magnetic organism. Trapped in orbit of Questar M-17, the crew disable their own ship to prevent the spread of the entity.

87 million years ago

 * The D'Arsay civilization launches the archive of their culture.

65 million years ago

 * Earth's dominant reptile superorder, the dinosaurs, are wiped out when an asteroid impacts the planet.
 * Some of Earth's dinosaurs survive the asteroid impact and continue to develop and name themselves the Voth. Sometime thereafter they leave Earth and travel to the Delta quadrant where they create one of the first interstellar empires in the quadrant.

20 million years ago

 * The recorded history of the Voth civilization begins in the Delta Quadrant.

1 million years ago

 * On Earth, the ancestors of Humans begin to distinguish themselves from their primate ancestors by their intelligence and reasoning skills.
 * Construction of the vast city around the Guardian of Forever, stretching out to the horizon of its planet. Spock estimated the age of the ruins to be "on the order of ten thousand centuries" in 2267.

Indeterminate

 * The inhabitants of Organia evolve to beings of pure energy.

600,000 years ago

 * The Tkon Empire collapses.
 * The humanoid ancestors of Sargon's race colonized the galaxy. Their colonists may have caused, or influenced, the rise of intelligent life on Vulcan.

500,000 years ago

 * Civilization first begins to flourish on Bajor.


 * Sargon's species is destroyed in a massive civil war when the atmosphere is ripped from their planet. Only a few survivors escape by preserving their consciousnesses in a cave deep below the surface.
 * The planet Exo III becomes nearly uninhabitable after its sun begins to fade. The inhabitants resettle beneath the surface and construct androids to serve them.

200,000 years ago

 * The Iconians, a highly developed civilization, are presumed destroyed in an orbital bombardment of their homeworld.
 * The large bioplasmic organism, dubbed as the "telepathic pitcher plant" is born in the Delta Quadrant.
 * By at least this point, the Borg have begun their evolution into cybernetic beings.

100,000 years ago

 * The subspace network which will be later claimed by the Hirogen is constructed by an unknown race.
 * The ocean planet, later home of the Monean civilization, is created by extracting all water from a Class M planet and containing it inside an immense force field.

50,000 years ago

 * The Horta of Janus VI begin their latest cycle of rebirth.
 * Bele begins to chase Lokai, who has led a revolution on the planet of Cheron.

45,000 years ago

 * Extraterrestrial visitors, known as the "Sky Spirits", visit a people on Earth who become the indigenous inhabitants of America.

30,000 years ago

 * The Verathan civilization, originally from the Verath system in the Gamma Quadrant, reaches its height, spanning two dozen star systems.
 * An ancient city was built on Bajor with walls and a tablet that were dated to be over thirty millennia old. This city was inhabited until twenty-five thousand years ago after which, sediment buried the ruins and the ancient city of B'hala was built on top of it.

28,000 years ago

 * On Earth, the Neanderthals become extinct.

22,000 years ago

 * The first of at least 947 archaeological expeditions is conducted at the ancient ruins on Tagus III.
 * The Trill begin their life as a joined species.

20,000 years ago

 * The Bajorans begin celebrating the Bajoran Gratitude Festival.


 * The Bajoran Holy City of B'hala is lost to history.

12,000 years ago

 * An artisan known only as the Master of Tarquin Hill on Kurl, during the Third Dynasty, creates small ceramic figurines, called naiskos, that embody that culture's belief that within each person is a community of individuals, each with its own desires, views, and voices.

10,000 years ago

 * According to Quinn, this was the last time that "ordinary" Q in the Q Continuum had to speak with each other.
 * When their sun is about to go nova, the Fabrini leave their system on a propelled asteroid known as the Yonada.
 * The machine-god Vaal on Gamma Trianguli VI is built.
 * The civilization on Sigma Draconis VI which is currently at its technological peak, advanced well beyond 23rd century Federation capabilities, experiences a catastrophic glacial age. As a result, the inhabitants of the planet begin to de-evolve to a primitive level, and the male and female inhabitants experience a great schism in their society.
 * A species of intelligent spacefaring organisms which form symbiotic relationships with humanoid lifeforms that live within their bodies become nearly extinct. Gomtuu is the last known survivor.
 * The first of the Orbs is discovered by the Bajorans in the sky above their planet. Over the next ten millennia, a total of nine of these extraordinary objects are discovered, inspiring revelations that shape Bajoran religion.
 * The Founders establish a new homeworld in the Omarion Nebula to escape prejudice and persecution founding the Dominion.
 * The Ferengi discover currency and the concept of profit. The first Grand Nagus, Gint writes the Rules of Acquisition during this time.
 * The Bajoran archaeologists begin their unsuccessful, ten thousand year search for the lost city of B'hala, which is not uncovered until the year 2373.

9,000 years ago

 * The Zakdorn earned a reputation as brilliant strategists.

6,000 years ago

 * The Aldeans build a massive cloaking device that shields their planet, Aldea, from outside detection.
 * circa 4000 BC: Unknown aliens take or abduct several Humans from Earth to be eugenically bred on a distant planet, lest humanity destroy itself in its early technological age. Gary Seven, Agent 201 and Agent 347 will be among their descendants.
 * 3834 BC: Akharin is born in Mesopotamia on Earth. A soldier felled in battle, he soon realizes that no injury can kill him. He goes on through many aliases, becoming the immortal known as Flint.
 * circa 3733 BC: Landru of Beta III preaches peace and coexistence among his people, ending a period of savagery. He creates a powerful computer to guide and protect his people after his death.

5,000 years ago

 * circa 2700 BC: Earth is visited by aliens who settle in the region near Greece and the Mediterranean, where they are worshiped by the Greeks as gods.
 * Sarpeidon experiences an ice age. Zarabeth is exiled to this time period, and Spock and Leonard McCoy are briefly stranded here as well.
 * By this time, Vulcans are still barbaric, war-like and "nearly killing themselves off with their own passions".


 * circa 2600 BC: The Egyptians build the pyramids of Giza. They are observed by anthropologists from the future (specifically, the year 2769).
 * Humans on Earth begin the tradition of confining law-breakers to prisons.
 * circa 2500 BC: Vulcans begin to mentally train themselves to suppress their emotions.

4,000 years ago

 * circa 1800 BC: The Xindi-Avians build a concealed fortress on a planet that will one day become the home of the Xindi Council.


 * circa 1735 BC: According to Spock, this is when Humans begin to glorify organized violence.

3,000 – 2,000 years ago

 * circa 950 BC: Flint lives the life of King Solomon on Earth.
 * circa 850 BC: The Vulcan monastery on P'Jem is built.
 * circa 730 BC: The Kalandan outpost planet, "a few thousand years old" in 2268, may be constructed around this time.
 * circa 500 BC: The Bajoran prophet Trakor first encounters the Orb of Prophecy and Change, and writes a series of prophecies concerning the Emissary of the Prophets.
 * 480 BC: The Battle of Thermopylae is fought on Earth between the Spartans and the Persians.
 * circa 400 BC: Survivors from the Sahndara system supernova arrive on Earth. Their sojourn coincides with the time of the philosophers Socrates and Plato. "After the death of the Greek civilization they idolized" they move on to the planet Platonius.
 * 356-323 BC: Flint lives the life of Alexander the Great on Earth.
 * 214 BC: Construction begins on the Great Wall of China on Earth.
 * 44 BC: Parmen, future leader of the Sahndaran refugee community, is born on Platonius.
 * 33 BC: Philana, future wife of Parmen, is born on Platonius.
 * 3 BC: Philana, now 30, stops aging.

Indeterminate past

 * An unknown race, possibly of extragalactic origin, builds a massive planet killer.
 * The population of Talos IV is largely wiped out in a war. Forced to live beneath the surface, the Talosians develop their mental powers, while neglecting their technological knowledge and skills.
 * According to Klingon mythology, Kortar, the first Klingon, destroys the gods who created him.
 * A neutron star in a binary star system in the Kavis Alpha sector begins exploding every 196 years.
 * A power struggle occurs within the highest ranks of a race called the Saltah'na, which ultimately destroys them. Before their extinction, the Saltah'na create a collection of energy spheres which preserve a record of the events leading to the species' destruction via a telepathic matrix, which can be transferred into the minds of some humanoid species, causing them to reenact the power struggle.