Victor Pierre Horta (6 January 1861 – 8 September 1947) was a Belgian architect and designer, and one of the founders of the Art Nouveau movement. He was a fervent admirer of the French architectural theorist Eugène Viollet-le-Duc and his Hôtel Tassel in Brussels (1892–93), often considered the first Art Nouveau house, is based on the work of Viollet-le-Duc. The curving stylized vegetal forms that Horta used in turn influenced many others, including the French architect Hector Guimard , who used it in the first Art Nouveau apartment building he designed in Paris and in the entrances he designed for the Paris Metro. He is also considered a precursor of modern architecture for his open floor plans and his innovative use of iron, steel and glass.