Main and big events in the Halo timeline.
10,100,000 BCE Forerunner/Precursor war takes place.
110,000 BCE The Flood powder is discovered.
110,000 BCE Human/Forerunner war.
101,000 BCE time when Diadact entered a cryptum.
101,000 BCE when the original 12 Halos were created.
100,300 BCE The first contact with Flood and forerunners.
100,000 BCE reseeding of the galaxy begins.
1945 The United Nations are formed.
2163 The United Nations Space Command is formed
2362 The planet Reach is colonized.
2489 Jul'Mdama is born.
2490 Terrance Hood is born.
2491 Tartarus is born.
2492 Catherine Halsey is born.
2495 Jacob Keyes is born.
2501 John Forge is born.
2510 Edward Buck is born.
2511 many Spartans II's are born, including John-117 and Jorge-052
2517 first day of Spartan II program begins
2525 The human/Covenant war begins
2525 Halo: Reach Plays out.
2525 Jorge-052 dies
2525 John-117 is awoken from cryo
2525 Chief gets cortana
2525 Buck and Dare the ODST's are deployed to new Mombasa
2525 The Elites join the humans against the Covenant.
2554 Buck becomes a spartan.
2556 Cortana descends into rampancy.
2557 UNSC Infinity is commissioned into service
2557 John-117 is awakened from cryo, crashed into Requiem and releases the diadact and Halo 4 plays out. What a year for Chief.
2527 Cortana is "destroyed".
2528 Fireteam Crimson is deployed to Requiem.
2528 Infinity is freed from Requiem and escapes.
2528 Jul'Mdama is killed by Spartan Locke in Fireteam Osiris.
2528 Master Chief is declared AWOL.
2528 Halo 5: Guardians ends.
2607 The Museum of humanity Begins construction and a statue of Master Chief is erected.