Ernesto de Sousa (Lisbon,  April 18, 1921 – October 6, 1988) was one of the most complex and active figures of his time, a prolific multidisciplinary artist and an avid producer of synergies between generations of artists from both the first and the second half of the 20th century. Defending an experimental and free artistic expression, he dedicated himself to the study, promotion and practice of the arts, as well as to curatorship, critique and essay writing, photography, cinema and theater.

During the 1960s he got in touch with the Fluxus movement and with the European neo-avant-garde, becoming friends with Robert Filliou and Wolf Vostell. This contact was significant to his recast of art as an experimental and participatory "open work", of which are examples the theatrical exercise Nós Não Estamos Algures (1969), the expanded film Almada, Um Nome de Guerra (1969-1972) and the mixed media Luíz Vaz 73, all collaborative pieces authored by him.

During this decade and up until the 1980s, he organized courses, conferences and exhibitions on experimental film, video art, performance and happening, while promoting connections between the international neo-avant-garde and the Portuguese context.

Ernesto de Sousa anticipated the Carnation Revolution (April 25th, 1974) and countered Portugal's peripheral position in Europe when he proposed to celebrate Robert Filliou's Anniversary of Art (Círculo de Artes Plásticas de Coimbra, 1974). The exhibition "Alternativa Zero" (Galeria Nacional de Arte Moderna, Lisbon, 1977) synthesized his project of creating a Portuguese avant-garde in aesthetic and ideologic dialogue with its international counterparts.

He published extensively in magazines and newspapers since the 1940s, and his critique was instrumental in encouraging experimental artistic practices in Portugal. His strong involvement in the film society movement, which he founded in Portugal, was a major contribution towards the outbreak of the "New Cinema" announced by his only feature film, Dom Roberto (1962), awarded twice at the Cannes Festival in 1963. It's also important to note his studies on Portuguese folk art and its theorization in the context of contemporary art as well as his rereading of the work of the "voluntarily ingenuous" artist Almada Negreiros, whose work anticipated the ideas De Sousa defended.

He was the Portuguese commissioner for the Venice Biennale in 1980, 1982 and 1984.

Dedicated to him were the retrospective exhibitions Itinerários, organized by the Secretary of State for Culture in 1987 (commissioned by José Luís Porfírio, Leonel Moura and Fernando Pernes), and Revolution My Body at Fundação Calouste Gulbenkian in 1998 (commissioned by Helena de Freitas and Miguel Wandschneider).

In 1997 the Serralves Foundation presented a restitution of "Alternativa Zero" on the celebration of the 20th anniversary of this exhibition, and in 2012 a restaging of the mixed media Almada, Um Nome de Guerra and Nós Não Estamos Algures.
In 2014 the José de Guimarães International Arts Center organized the exhibition "Ernesto de Sousa e a Arte Popular – Em torno da exposição 'Barristas e Imaginários'".

From 1992 to 2013, the Ernesto de Sousa Fellowship supported 20 young artists in the making of intermedia projects during an internship at the Experimental Intermedia Foundation in New York.