The Supreme Alliance of Eastern States was a 51st century political coalition of nations opposed to the Icelandic Alliance. A brutal regime, Magnus Greel served as the Supreme Alliance's Minister of Justice. While working for the Alliance, the alien scientist Dr. Sa Yy Findecker pioneered time travel through the use of the Zygma beam, though this eventually turned out to be a dead end.

The Supreme Alliance brought down the Icelandic Alliance by having its commissioner Ingrid Bjarnsdottir killed by the Peking Homunculus, which nearly precipitated World War VI. The Supreme Alliance itself fell after the Filipino Army advanced on Reykjavik, an event which either the Fourth Doctor or one of his three incarnations witnessed. Using information provided by his fifth incarnation, the Doctor was able to avert the outbreak of war. (TV: The Talons of Weng-Chiang, AUDIO: The Butcher of Brisbane)

In the Icelandic Alliance, it was commonly referred to as "the Southern Alliance." (AUDIO: The Butcher of Brisbane)

Greel used a time cabinet to escape to 19th century China. The cabinet eventually fell into the possession of George Litefoot's father. Following his death, the younger Litefoot inherited it and brought it with him back to London, where it remained until 1889. (TV: The Talons of Weng-Chiang)