Semper Human

50,000,000–30,000,000: Galaxy dominated by the One Mind, sentient organic superconductors with hive mentality. They create the network of stargates across the Galaxy, and build the Encyclopedia Galactica Node at the Galactic Core.

30,000,000–10,000,000: Dominance of Children of the Night, nocturnal psychovores. They replace the One Mind, which may have transcended material instrumentality.

10,000,000 TO PRESENT: Dominance of the Xul, also known as the Hunters of the Dawn. Originally polyspecific pantovores, they eventually exist solely as downloaded mentalities within artificial cybernetic complexes.

Circa 500,000 B.C.E.: Advanced polyspecific machine intelligence later called variously the Ancients or the Builders extends a high-technology empire across a volume of space several thousand light years in extent. Extensive planoforming of Chiron, at Alpha Centauri A, of Mars in the nearby Sol System, and of numerous other worlds. QCC networks provide instantaneous communications across the entire empire. Ultimately, the Builder civilization is destroyed by the Xul. Asteroid impacts strip away the newly generated Martian atmosphere and seas, but Earth, with no technological presence, is ignored. A Xul huntership is badly damaged in the battle over Mars; it later crashes into the Europan world-sea and is frozen beneath the ice. Survivors of the Martian holocaust migrate to Earth and upload themselves into gene-tailored primates that later will be known as Homo sapiens.

10,000 B.C.E.–7500 B.C.E.: Earth and Earth’s Moon colonized by the Ahannu, or An, who are later remembered as the gods of ancient Sumeria. Around 7500 B.C.E., asteroid strikes by the Xul destroy An colonies across their empire. Earth is devastated by asteroid strikes. One colony, at Lalande 21185, survives.

Circa 6000 B.C.E.: Amphibious N’mah visit Earth and help human survivors of Xul attack develop civilization. They are later remembered as the Nommo of the Dogon tribe of Africa, and as civilizing/agricultural gods by other cultures in the Mideast and the Americas.

Circa 6000–5000 B.C.E.: N’mah starfaring culture destroyed by the Xul. Survivors exist in low-technology communities within the Sirius Stargate and, possibly, elsewhere.

1200 B.C.E. [SPECULATIVE]: The Xul revisit Earth and discover an advanced Bronze Age culture. Asteroid impacts cause devastating floods worldwide, and may be the root of the Atlantis myth.

700 C.E.: The deep abyssal intelligence later named the Eulers fight the Xul to a standstill by detonating their own stars. This astronomical conflagration of artificial novae is seen in the skies of Earth, in the constellation Aquila, some one thousand two hundred years later.

2039–2042: Semper Mars

2040: 1st UN War. March by “Sands of Mars Garroway.” Battle of Cydonia. Discovery of the Cydonian Cave of Wonders.

2040–2042: Luna Marine

2042: Battle of Tsiolkovsky. Discovery of An base on the Moon.

2067: Europa Strike

2067: Sino-American War. Discovery of the Singer under the Europan ice.

2138–2148: Star Corps

2148: Battle of Ishtar. Treaty with An of Lalande 21185. Earth survey vessel Wings of Isis destroyed while approaching the Sirius Stargate.

2148–2170: Battlespace

2170: Battle of Sirius Gate. Contact with the N’mah, an amphibious species living inside the gate structure. Data collected electronically fills in some information about the Xul, and leads to a Xul node in Cluster Space, thirty thousand light years from Sol. A Marine assault force uses the gate to enter Cluster Space and destroy this gate.

2314–2333: Star Marines

2314: Armageddonfall

2323: Battle of Night’s Edge. Destruction of Xul Fleet and world in Night’s Edge Space.

2877: Star Strike

2877 [1102 M.E..]: 1MIEF departs for Puller 695. Battle of Puller 695 against Pan-Europeans. Contact with Eulers in Cygni Space. Battle of Cygni Space. Destruction of star in Starwall Space, eliminating local Xul node.

2886: Galactic Corps

2886 [1111 M.E.]: Raid on Cluster Space by 1MIEF. Discovery of stargate path to major Xul node at Galactic Core.

2887 [1112 M.E.]: Operation Heartfire. Assault on the Galactic Core.

4004: Semper Human

3152: Volunteer elements of the Marine third Division enter extended cybernetic hibernation.

3214: Formation of the Galactic Associative.

4004 [2229 A.M.]: Dahl Incursion. Contact with the Tarantulae. Attack on Xul presence within the Quantum Sea. Xenophobe Collapse.

4005 [2230 A.M.] Re-establishment of the United States Marine Corps.