In 1957 lifelong conscientious objector Rumney was one of the co-founders of the London Psychogeographical Association. This organization was, along with COBRA and the Lettrist International, involved in the formation of the Situationist International. Amongst those present at the founding in the Italian village of Cosio d'Arroscia were Walter Olmo, Michèle Bernstein (to whom Rumney was later married ), Asger Jorn, and Guy Debord. However, within seven months Rumney had been 'amiably' expelled from the SI by Debord for allegedly "failing to hand in a psychogeography report about Venice on time."
Rumney spent much of his life living as a wanderer, and was variously described as both a 'recluse' and a 'media whore', seeing his existence as a 'permanent adventure and endless experiment.' He moved, as his friend Guy Atkins said, "between penury and almost absurd affluence. One visited him in a squalid room in London's Neal Street, in a house shared with near down-and-outs. Next, one would find him in Harry's Bar in Venice, or at a Max Ernst opening in Paris. He seemed to take poverty with more equanimity than riches."
The Map Is Not The Territory by Alan Woods and Ralph Rumney (Manchester University Press, ISBN 0-7190-5951-8) was published in 2001. The Consul by Ralph Rumney, a book of interviews conducted by Gérard Berreby (Verso, ISBN 1-85984-395-6) published in 2002.