Semsar Siahaan (1952–2005) was an artist and humanitarian as well as a seminal voice in Indonesia’s anti-authoritarian progressive movement of the 1990s. At the intersection of art and activism, his work embodies mass struggle for justice against the nation’s corporate and political leaders. The paintings, drawings and installations produced throughout his decades-spanning career showcase the artist’s deep engagement with Indonesia’s history and political legacies, his keen eye for social commentary and his front-line experience during a time of great national unrest. Even when in exile in Canada and towards the end of his life, he remained committed to portraying the sociopolitical injustices that afflicted both the individual and the collective.