The Fourth Great and Bountiful Human Empire was an empire at a time when Earth was (supposedly) at its height. The planet itself, covered in megacities, had ninety-six billion inhabitants and five artificial moons. Its influence supposedly spread across "a million planets and a million species".
The Fourth Great and Bountiful Human Empire flourished with millions of species, good manners, fine food, cutting edge technology, and "mankind right in the middle". At least, that was how it was supposed to be according to the Ninth Doctor, but something altered history. Circa 199,909, the Mighty Jagrafess of the Holy Hadrojassic Maxarodenfoe was installed into the ceiling of Floor 500 of Satellite Five, a space station broadcasting across the empire, where it manipulated news reports and kept humanity docile, ignorant, and under its control with the help of a human lackey called the Editor. (TV: The Long Game)
Ninety-one years later, circa the year 200,000, the Ninth Doctor, Rose Tyler, and Adam Mitchell visited Satellite Five. Cathica Santini Khadeni, a human acting as a processor for the computer system which broadcast all the news from the satellite, destroyed the Jagrafess by directing the heat to Floor 500, causing the immense Jagrafess to overheat and explode. (TV: The Long Game) By 200,100, the Earth economy had collapsed after the destruction of the Jagrafess. After the death of the Jagrafess, the Dalek Emperor was secretly in charge of Earth.
Earth still hadn't developed to its proper level. In the meantime, Satellite Five had been renamed the "Game Station". While the Dalek influence was ended when the Dalek Emperor was slain by the Bad Wolf entity Temporal paradox, the damage to Earth in the conflict was massive, mostly due to Dalek bombings destroying entire continents of the Earth. (TV: The Parting of the Ways)