Jean Delhaye studied under Victor Horta during his last years as a teacher at the Royal Academy of Fine Arts, before joining Horta's architecture studio in 1934. From the 1950s onwards, he waged a dogged campaign to preserve the buildings of his former mentor, of which he was a passionate admirer. He also saved what remained of Horta's writings as well as many pieces of furniture, fragments of demolished buildings and a number of plaster casts. It was on his initiative that Horta's home and studio were turned into the Horta Museum in 1969. Jean Delhaye played a vital role in the posthumous recognition of the Art Nouveau master and in the promotion of Belgian Art Nouveau internationally.