Documented: Browning's Andrea del Sarto (1855), Men and Women, line 78 in most printings: the painter, technically perfect and spiritually outrun by Raphael, murmurs well, less is more, Lucrezia while excusing his own timid perfection. The phrase's first life is an apology for caution, spoken by a man who knows exactly what he traded away.
Documented: Mies van der Rohe adopted the phrase as the doctrine of his architecture, beinahe nichts, almost nothing, and used it publicly from the 1940s, with Philip Johnson and the International Style spreading it into the corporate century. Mies's biographers trace his usage to his circle's reading of Browning. The glass skyline of every city is the poem's descendant.
The documented revolt: Robert Venturi answered in 1966 with less is a bore, and postmodernism, minimalism's critics, and every maximalist since have fought over a line that began as one Renaissance husband's sigh. The archive notes the full genealogy: a poem about artistic cowardice became modernism's spine, then postmodernism's target, then a throw pillow.
When a compromise becomes a commandment, what got edited out?