51st century

In the 51st century, humanity began to spread into the galaxy and to deal with time travel.

Another Ice Age affected Earth during this time. (TV: The Talons of Weng-Chiang, PROSE: Emotional Chemistry, AUDIO: The Butcher of Brisbane)

Earth began to be abandoned by the rich and powerful as the sun went supernova. Those left behind were fractured into millions of nation-states ("Alliances") battling through the ether in the Transmat Wars. (COMIC: The Keep)

Humanity was sexually liberal, widely accepting both same-sex relations and inter-species ones. (TV: The Doctor Dances) Human bodies in this period evolved to produce more highly evolved pheromones, which made them more sexually attractive than their ancestors. (TV: Day One, Fragments)

The Church was a faith-based military organisation primarily responsible for interstellar security, protecting human populations, and special covert operations. Regular military ranks were replaced by offices such as Bishop, Cleric and Verger. (TV: The Time of Angels, Flesh and Stone)

The Time Agency operated out of this century, but it was closed again in the same century. (TV: The Talons of Weng-Chiang, The Empty Child, TV: Kiss Kiss, Bang Bang)

Law and order collapsed in this century. Derek O'Dell, a fan of the 20th century comic book Aggrotron, adopted the identity of Courtmaster Cruel, a character from the comic, to strike fear into the hearts of criminals. (AUDIO: Izzy's Story)

Major events
5000 was the year of the Great Breakout. Humanity spread through the Galaxy. (TV: The Invisible Enemy)

Ionisation was used to combat the glaciers caused by the Ice Age, and the Brittanicus Base was established by this time. (TV: The Ice Warriors)

The Supreme Alliance of Eastern State, at the initiative of its Minister of Justice Magnus Greel, experimented with time travel using a method developed by the alien scientist Dr. Sa Yy Findecker based on double nexus particles and zygma beam, but this proved to be a dead end. Greel was said to be the first human to travel through time, arriving in China during the 19th century, but became horribly disfigured by it. (TV: The Talons of Weng-Chiang, AUDIO: The Butcher of Brisbane)

In the early 51st century, the Icelandic Alliance fell and the Supreme Alliance of Eastern States, of which Magnus Greel was Minister of Justice, rose in its stead. The Supreme Alliance committed a number of war crimes and was brought down by the Filipino Army at the Battle of Reykjavik, which the Fourth Doctor witnessed. (TV: The Talons of Weng-Chiang, AUDIO: The Butcher of Brisbane)

Also in the early 51st century, Magnus Greel killed approximately 100,000 people, a deed which earned him the epithet "Butcher of Brisbane". (TV: The Talons of Weng-Chiang) Consequently, the area became known as the Brisbane Dead Zone. (AUDIO: The Butcher of Brisbane)

Minor events
The weapons factories of Villengard were destroyed by the Doctor and replaced by a banana grove. (TV: The Doctor Dances)

The spaceship SS Madame de Pompadour became disabled. Adrift in the Dagmar Cluster, its Clockwork Droids repaired the ship using whatever they could find, including the crew, and attempted to kidnap the original Madame de Pompadour from the 18th century to use her brain as their computer core. (TV: The Girl in the Fireplace)

The Eleventh Doctor and Amy Pond, along with River Song witnessed the crash of the Byzantium, then confronted the last of the Weeping Angels in the Maze of the Dead. (TV: The Time of Angels / Flesh and Stone)

The Tenth Doctor and Donna Noble visited the Library where they faced an infestation by the Vashta Nerada. The Doctor met River Song for the first time in his personal timeline (but not in hers). River retrieved the consciousnesses of some 4,022 humans who were uploaded to the memory banks of the supercomputer, CAL, and died. (TV: Silence in the Library / Forest of the Dead)

Notable individuals
Jack Harkness, John Hart, Gray and Magnus Greel all came from this century. (TV: The Talons of Weng-Chiang, The Doctor Dances, Kiss Kiss Bang Bang, Adam)