This great dress was designed by Yves Saint Laurent, the well-known French couturier, for his fall-winter collection of 1965-66.  Saint Laurent was born in Algeria in 1936, and would later in his life live in Morocco (see my earlier post on Saint Laurent’s fantastic garden in Marrakech), which gives his life a kind of North-African symmetry.  He called this The Mondrian Day Dress, 5.

In the mid-1950s, designers started playing around with dress shapes, and the “sack dress” like this one by Christian Dior evolved as a fashionable new version of the shift. Saint Laurent had worked within this framework but was evolving away from the looseness of the format.  Of course, the French designer was also familiar with the flat planes of color in paintings by Piet Mondrian.

So, Saint Laurent began boldly borrowing Mondrian’s color block idea and added it to the new shift design with which he…