Empire (Nightmare in Silver)

A human empire fought the Cybermen in the far future. (TV: Nightmare in Silver)

History
The empire was ruled by Emperor Ludens Nimrod Kendrick Cord Longstaff XLI, also known as "Porridge". He succeeded the old Emperor, whom he had accompanied when he, protected by the Imperial Guard, attended the ice picnic on Caspertine. where the snow bears danced for them. (TV: Nightmare in Silver)

Behind the scenes
Though not stated in the episode, writer Neil Gaiman revealed that he set Nightmare in Silver as taking place "a quarter of a million years into the future." This would place the empire beyond the timeframe of the Fourth Great and Bountiful Human Empire, dated by the Ninth Doctor to the year 200,000 in The Long Game.