Marwan grew up in Damascus in Syria and studied Arabic literature at the University of Damascus from 1955 to 1957. In 1957, at the age of 23, he moved to Berlin and began studying painting in Hann Trier's class at the Hochschule für Bildende Künste, where he soon met Eugen Schönebeck and Georg Baselitz. In 1967, Marwan had his first solo exhibition at the Springer Gallery in Berlin and from 1971 was represented by the Lietzow Gallery in Berlin. From 1977 to 1979 Marwan was a visiting professor for painting at the Hochschule der Künste in Berlin and was appointed professor there in 1980. He held this office until his retirement in 2002. Marwan's work can be seen in numerous individual shows, including at the Arab Cultural Centre in Damascus (1970), the Orangerie Schloss Charlottenburg in Berlin (1976), the Museum of Modern Art in Baghdad (1980), the Kunsthalle Darmstadt (1984), the Berlinische Galerie in Berlin (2006/07), the Museum for Islamic Art in Berlin (2008), the Haus am Waldsee in Berlin (2009), the Tajalliyat Art Gallery in Damascus (2010) and the Beirut Exhibition Centre (2013). In 2017 his work was shown in a major presentation at the exhibition "Viva Arte Viva" at the 57th Venice Biennale. Marwan was awarded the Karl Hofer Prize in 1966, followed by the Fred Thieler Prize for Painting in 2002. In 2005 he received the Order of Merit of the Federal Republic of Germany for his artistic work and his social engagement.