Theo van Doesburg

Theo van Doesburg founded De Stijl in 1917 and used the magazine of the same name to promote geometric abstraction. He helped connect painters, architects, and designers around a shared language of straight lines, grids, and primary colors.

Van Doesburg pushed De Stijl beyond Mondrian's stricter vertical and horizontal compositions by introducing diagonals in what he called Elementarism. That disagreement helped mark a split between their approaches to abstraction.

No. He was also a theorist, editor, designer, poet, and architectural collaborator. His work moved through Dutch, German, and French avant-garde circles in the 1910s and 1920s.

His writing and organizing helped spread De Stijl ideas into architecture, typography, and interior design. The movement's emphasis on grids and reduced form still echoes in modernist design education.