The Timeline as presented by H.Beam Piper is different i several aspects.
TERRO-HUMAN FUTURE HISTORY CHRONOLOGY
1 A.E. (1942) Year one of the Atomic Era, which begins when the first atomic pile goes into operation under the direction of Enrico Fermi at the University of Chicago.
29 A.E. (1971) The first unmanned rocket, the Kilroy, is launched.
32 A.E. (1974) The first Lunar base is completed.
32 A.E. (1974) The Thirty Days War; the First Terran Federation is formed.
54 A.E. (1996) The First Mars Expedition.
92 A.E. (2034) Contragravity is developed.
108 A.E. (2050) The Mars Colony is established.
116 A.E. (2058) The first colony on Venus is started.
144 A.E. (2086) The first intersteller expedition.
174 A.E. (2116) Venus seceeds from the Terran Federation.
183 A.E. (2125) The First Terran Federation is dissolved and the Second Terran Federation is established.
782 A.E. (2724) Foxx Travis is born, The Cosmic Computer/Junkyard Planet.
809 A.E. (2751) Native revolt on Kwannon?.
812 A.E. (2754) Aditya? is discovered.
842-854 A.E. (2784-2796) The System States War, starts when the System States Allliance tries to break away from Federation Control, Space Viking.
854 A.E. (2796) Ten thousand refugees from Abigor? flee with the remnants of the System States Navy to found a new civilization. They colonize Excalibur?, the first Sword-World, Space Viking
894 A.E. (2836) Merlin, the great Federation battle computer is located on Poictesme?, Junkyard Planet
1000-1399 A.E. (2942-3341) The Intersteller Wars, a series of revolts and wars that lead to the collapse of the Terran Federation.
1503 A.E. (3445) Six Space Viking ships from Haulteclere? raid Aton?; four of their ships are destroyed and two others limp home. After this failure, the Space Vikings no longer raid civilized worlds.
1548 A.E. (3490) During a war between Aton? and Baldur?, the Planetary Nationalist Party on Aton takes power and forms a dictatorship.
1604 A.E. (3446) The Nemesis spaceship is built and Lucas Trask Leaves Gram? for Tanith? in the Old Federation.
1611 A.E. (3553) The Battle of Audhumla?.
1613 A.E. (3555) Omfray of Glaspyth, with a fleet of eight Space Viking ships, land on Gram?.
1613 A.E. (3555) The Battle of Marduk?
1848 A.E. (3790) King Stephen IV becomes the first Galactice Emperor.
1904 A.E. (3846) The Sword Worlds are added to the Empire.
1936 A.E. (3878) Emperor Paul II begins building the Imperial palace on Odin.
2162 A.E. (4104) Rodrik IV completes the consolidation of the First Galactic Empire.
2936 A.E. (4878) Paul XXII tries to move the Empire out of its complacent rut.