Henningsen studied architecture at the Copenhagen Technical School and the Danish College of Technology. He opened an office in 1920; some early commissions included private houses, a factory, two theater interiors, and a section of the Tivoli Gardens.

A complex man of many talents, he became a Danish national institution during his lifetime, active as an author, poet, playwright, songwriter, theatrical producer, editor, and social critic. A cantankerous chain smoker, he disliked many conventions of modern life—particularly the incandescent bulb and the brash excess it facilitated—spawning what he described as an urban landscape "wallowing in light".

This conviction, present from the beginning of his career, inspired him to experiment with lighting design in the 1920's, and eventually to create his famous PH lamp (1924). Its light diffusing saucers insured flattering, uniform illumination; a revelation compared to ordinary fixtures of the day. Exhibited to great acclaim in Paris in 1925, it attracted attention from several prominent architects and designers, including Alvar Aalto and Mies van der Rohe; the latter used it in the interiors of the Tugendhat House. Page 2 >