Futurist architecture began in the early 20th century as a rejection of traditional styles and an embrace of modernity and technology. Antonio Sant'Elia was a key figure who translated the Futurist vision into bold urban designs, though most remained unbuilt. His 1914 Manifesto of Futurist Architecture advocated for an architecture of steel, glass and other modern materials that incorporated dynamic oblique lines over static horizontals and verticals. Sant'Elia's visionary but unbuilt works were highly influential and helped establish the foundations for modern architecture in the mid-20th century.