Yesterday afternoon I was at the National Portrait Gallery's ongoing exhibition Inventing Marcel Duchamp: The Dynamics of Portraiture. Marcel Duchamp (1887–1968), whose name appeared on this blog before, was one of the founders of the Dadaist movement early in the 20th century.
The exhibition consisted primarily of portraits of Duchamp from the 1910s until a few years ago. Below is Mark Tansey's The Enunciation (1992). Marcel Duchamp and his female alter ego Rrose Sélavy are facing each other from passing trains.
Here is a poster Duchamp himself created in 1923.
This is one is Proposition for a posthumous portrait by Douglas Gordon (2004). The star in the back of the skull is in reference to a peculiar comet-shaped haircut Duchamp had in 1919 (photo).
Duchamp stopped producing public art in the 1920s, but remained an influential figure among artists. At the same, during the last 2 decades of his life he worked secretly on his final work, Étant donnés, that was unveiled only after his death.
More info on Duchamp and his work is available here and here.