The Sov Block city of East-Meg One was a huge sprawling conurbation with Moscow as its nucleus. It was similar to Mega-City One, the American mega-city centred on New York, but with an even more autocratic and repressive government (think Stalinism with jetpacks).
Notable citizens of East-Meg One included Viktor Zadek, a psychic who attempted to overthrow the brutal Marshall Kazan, and Orlok, the assassin who started the city's war with Mega-City One by poisoning the latter's water supply in 2103 AD. When Mega-City One tried to hit back it discovered that East-Meg One was protected by the 'Apocalypse Warp', a force field made from a dimension warp which sent any missiles that hit it into a parallel dimension, destroying that dimension's Earth and its peaceful inhabitants.
East-Meg One killed half of the Big Meg's citizens and appeared to be winning the war until Judge Dredd, with the help of Judge Anderson, infiltrated a Sov missile silo and nuked East-Meg One into a charred cinder. Nearly all of its 500 million citizens were killed and the city now no longer exists, with only a huge crater surrounded by a radioactive waste land scarring the earth where once its titanic skyscrapers loomed.
Survivors of East-Meg One have been seeking revenge ever since their city was obliterated. Their most successful attempt was the 'Day of Chaos', when they killed 350 million citizens of Mega-City One with a virus.