What It Set Loose

Is Black Square the most important painting of the century or the boldest art-world bluff? People still argue. Either way, its reach is hard to deny:

• It made concept count as much as craft, opening the door to conceptual art
• It fed later movements from the Bauhaus to minimalism
• The Soviet state turned against Malevich, and he died poor in 1935

A single square, and the rules of what counts as art were never quite the same.