Golden Age of Humanity
From Gineipaedia, the Legend of Galactic Heroes wiki
The Golden Age of Humanity (Japanese: 人類の黄金時代) was a period of human history lasting from 1 UC (2801 CE) to 201 UC (3001 CE), coinciding roughly with the first two centuries of the Galactic Federation.
Background
After nearly three hundred years of perpetual civil war and chaos, the reunification of humanity by the Galactic Federation ushered in a new age of peace and prosperity for the human race. The arts and sciences advanced dramatically: Federation starships explored and colonized the Frontier Worlds along the furthest reaches of the galactic rim, and in the densest regions of the galactic core. (LOGH: 'Julian's Journey, Mankind's Journey')
Aftermath
Eventually, the progressive attitudes that had characterized the Federation's golden age begin to wane: the Galactic Federation became increasingly conservative as society stagnated and degenerated. Exploration decreased dramatically, as well as scientific discoveries and invention. The steady expansion of Federation territory also ground to a halt.
The people of the Federation became increasingly decadent, and lost interest in politics and the advancement of humanity. The average number of accidents and violent crimes escalated, and the arrest rates decreased in inverse proportion. Some historians blamed this on a lack of religious faith. E.J. Mackenzie, a professor of ideological history, said, "The influence of religion fell dramatically after the unification of Earth. Even during the apocalyptic time of the Thirteen Day War and subsequent Ninety Year War, no saviour appeared. No god descended to Earth. All realized that no divine being would save them."
D. Sinclair, a professor of modern history, said, "Those who were concerned were not mistaken: the illnesses of society needed drastic treatment, but they were mistaken in their choice of remedy. Rather than a long term cure... they chose a strong medicine that granted quick relief, but was accompanied by undesirable side effects." The people of the Galactic Federation began to believe that the only way to save the Federation was to transform it into a dictatorship. The man they chose to invest absolute authority in was Rudolf von Goldenbaum."
Whatever the reasons, the Federation began to decay, eventually leading to the autocratic reforms of Rudolf von Goldenbaum and the creation of the Galactic Empire in 310 UC (1 IC / 3110 CE). (LOGH: 'Julian's Journey, Mankind's Journey')
Legacy
The Golden Era saw the human race extend across the width of the Orion Arm of the galaxy, and despite a few setbacks (like the Pirate Wars) the Golden Age would be remembered for centuries as a time of unprecedented peace and prosperity for all of humankind.
People in both the Galactic Empire and Free Planets Alliance saw the Golden Age as an envious era, a glorious past unequally by contemporary achievement. The first century of the Alliance's history, being a period of peace and unhindered growth, was likened to this golden age.