Of German ancestry, he was born in Liege on 29 March 1930. His grandfather was conductor at the city's opera. Julien Haas joined the church choir at the age of seven. He studied solo singing under Frédéric Anspach at the Conservatory of Liege. He won awards at international singing competitions in Belgium (1951) and Toulouse (1954), as well as the "Ansseau" Prize of the Conservatory of Brussels (1952). He first appeared at the Royal Monnaie Theatre in Brussels in 1954, interpreting a supporting role in the opera Boris Godunov. After performing a series of secondary roles, he relocated to France in 1956, where he made successful appearances at the Théâtre du Capitole de Toulouse, in Bordeaux and Nice. In 1959 (or 1961) he made his debut at the Paris Grand Opera as Rigoletto (Rigoletto) and, then, as Escamillo (Carmen), Scarpia (Tosca), Chorebus (Les Troyens), Thoas (Iphigenie en Tauride), Valentin (Faust), Creon (Antigone), Wolfram (Tahnnhäuser), Rodrigo (Don Carlo), Creon (Médée), etc. He had a brilliant career in Paris. At the same time, he also appeared in San Francisco, Los Angeles, Buenos Aires, Berlin and Dublin. Together with his wife, soprano Andrée Esposito, he taught voice at the Conservatory of Strasbourg. He has participated in the recordings of the following works: Les dragons de Villars by Aimé Maillart and Panurge on the Island of Lanterns (Panurge dans l’île lanterns) by André Grétry (DECCA). He died in 2008. At the GNO he appeared in 1965/66 as Lescaut (Manon) and Giorgio Germont (La traviata) alongside his wife in the role of Violetta. // Last update of the biography: November 2018 - The list of the productions below is complete.