Architect, writer, poet, visual artist, film director, theoretician, a prominent protagonist and an important catalyst of the unofficial neoavantgarde movement appearing in Hungary with new forms of expression at the second half of the sixties.

In 1947 he began his training as sculptor at the Academy of Fine Arts in Budapest, but he left soon due to the takeover of socialist realist approach, and continued his studies in the studio of Dezső Birman Bokros. From 1947 to 1951 he studied architecture at and graduated from the Technical University in Budapest. During the fifties and early sixties he worked as an architect at different companies, and besides he began experimenting with painting and graphic art, as well as writing poems and shorts stories.

During this period he became acquainted with the former members of the Európai Iskola (European School - among others Endre Bálint, Dezső Korniss), with the representants of the so called "surnaturalism" (among others Tibor Csernus, László Lakner) and, most importantly with the graphic artist Béla Kondor, the poet János Pilinszky and the painter Sándor Altorjai, with whom he began a lifelong friendship. In 1959 and 1963 he became enrolled at the Academy of Theatre and Film in Budapest, but he was advised to leave before the term to began, both times.

In 1966 he published a study on montage theory, where he emphasized the role of repetition and change, introduced the principle of “meaning negation” and its admission of the role played by intuition and inspiration. Since this publication some of his theoretical writings were published in Hungary (but none of his literal works). His first recognition as a writer and poet was the Kassák Prize of the Magyar Műhely (Hungarian Workshop) magazine issued in Paris. On this occasion they published his collected poems as well in 1974 (this was his only book printed during his lifetime).

He worked out a technology to create large decorative wall-covers called photomosaic, which provided him financial independence during the seventies and the eighties. Due to his interest in natural history, philosophy and language theory he turned toward conceptual art. In the late sixties and early seventies he took part in a number of then peripheric, but later canonized exhibitions and programs (Iparterv, Chapel Studio of Balatonboglar etc.) with his “textual actions” and photo-series accompanied by texts.

His interest in scientific thinking, researches in artistic and scientific cognition and the underlying affinities he found between them, his openness to old and new traditions and his intention to reinterpret them led him to state that his artistic activity is a continuous protest against the information blockade observed by him during the seventies. In his art he aimed to reveal, make easily accessible otherwise complex, unclear relationships. He also began to make films, based on his montage theory, in the framework of the Béla Balázs Studio, although none of his films was shown officially in Hungary until the eighties.

During 1975 and 1976 he ran a series of so-called "creative exercises". From these activities grew out in 1978 the INDIGO (in Hungarian: INterDIszciplináris GOndolkodás, “interdisciplinary thought”) group, which was conceived as an experimental teaching studio, drawing on modern artistic processes, educational methods influenced by Eastern philosophical traditions and many other sources. The problem-solving exercises, open to new and unusual pehnomena provided an important forum for a new generation of Hungarian artists, such as András Böröcz, Ildikó Enyedi, László László Révész, János Sugár, János Szirtes, among others.

It was only in the eighties, however, that Erdély achived public recognition for his work. He participated in several larger scale exhibitions with his drawings, paintings, and installations, and gave several lectures. His first solo exhibition opened in 1986, but he could not attain the opening due to his ingravescent illness.