The testimony of Joan Mercadé (Roda de Berà, 1935) is that of the son of a prisoner. His mother, Teresa Rius Colet (Roda, 1912), was arrested in 1939 while attempting to reunite with her husband, Josep Mercadé Arall, who had already escaped to France and would later be exterminated in the Nazi camp of Mauthausen, in the Gusen subcamp, in 1941.

His memories are those of a post-war child, visiting his mother in Les Corts prison in the company of his aunt. After spending more than a year and a half in prison, marginalized for political reasons, Teresa was unable to rebuild her life in Roda and had to return to Barcelona, where she began working in a textile factory. At twelve years old, Joan joined his mother and started working while learning a trade. At sixteen, he began working for a multinational company as an administrative employee, where he remained until his retirement.

At the age of twenty-five, he traveled to Paris in search of his father’s fellow inmates from Mauthausen who had survived. Thanks to the informal network of Teresa's former prison companions, the family preserved for decades an important document: the transcription of the last letter written by Carme Claramunt Barot, a native of Roda and a resident of Badalona, before her execution in 1939.

Over the years, Joan has been involved with Catholic, social, Catalan nationalist, and political associations. He is currently active in various citizen movement associations and is a founding member of the republican association També Hi Som.

Only recently, through contact with Carme's relatives and the intervention of historian Emili Ferrando, did the original prison chapel letter of Carme Claramunt, transcribed in the document preserved by Joan, come to light.

With the help of his son Lluc Mercadé Romeu, Joan prepared a biography of his father for the project The Digital Memorial Book for the Dead of the Mauthausen Concentration Camp and its Subcamps by the Mauthausen Memorial. Joan Mercadé Arall's name is now remembered in the Room of Names at the Mauthausen Memorial.