During his teenage years he learned to sing and to read music while in the church choir at the Ignatius Gymnasium, a prestigious Jesuit school in Amsterdam.
Through the Bergense School he was introduced to the work of Paul Cézanne, which impacted him deeply, as evident in Zelfportret (Self Portrait), 1942.
During this period Constant went into hiding and refrained from registering at the Kulturkammer (Nazi Chamber of Culture) to avoid the Arbeitseinsatz (labour supply for the Germans).
After the war, Constant, his wife and son moved back to Bergen only to return to Amsterdam in 1946 where they lived in an apartment across from the zoo Artis.
[1] In 1946 Constant travelled to Paris for the first time where he met the young Danish painter Asger Jorn.
[7] July 1948 Constant founded Reflex Experimentele Groep in Holland [nl] with Corneille, Karel Appel and his brother Jan Nieuwenhuys.
He had deducted this from the French word 'expérience' and believed that art springs from experience of the artist and is continuously changing.
In the manifesto he stated that the process of creation is more important to the experimental artist than the work itself; it is a means to reach spiritual and mental enrichment.
[9] Later in the year 1948 on the terrace of café Notre Dame in Paris the Experimentele Groep in Holland linked up with Christian Dotremont and Joseph Noiret from Belgium and Asger Jorn from Denmark to form CoBrA, a name which was made by Dotremont, formed by the first letters of their hometowns: Copenhagen, Brussels and Amsterdam.
This manifesto contains another of his famous quotes: "A painting is not a structure of colours and lines, but an animal, a night, a cry, a man, or all of these together".
In 1948 Constant, together with poet Gerrit Kouwenaar, published a poetry album Goede Morgen Haan.
Constant, Corneille, Appel and Eugène Brands created several large pieces of art that have become iconic for the movement.
With Aldo van Eyck, whom he met during his CoBrA time, he created a space for the exhibition 'Man and House' at the Urban Museum Amsterdam from 1952-1953.
In 1952 Constant received a scholarship from the Arts Council of Great Britain to study in London for three months.
There he met, amongst others, Henry Moore, Anthony Hill, Kenneth Martin, Ben Nicholson, Barbara Hepworth, Roger Hilton and Victor Pasmore.
He felt that the constructions of his time were mostly practical, immensely dull and provided no room to develop playful and creative lifestyles.
He objected to the SI on the ground that the movement seemed to be established mainly by artists who have their own interest at heart more than a common goal.
Back in Amsterdam after his stay in London, Nieuwenhuys started to focus mainly on architecture and the urban environment.
The focal point of his work was finding out what potential added value art can provide in intensifying daily life, in which there is room for creative expression.
New Babylon is inhabited by homo ludens, who, freed from labor, will not have to make art, for he can be creative in the daily practice of his life.
[13] In Nieuwenhuys' own words: The project of New Babylon only intends to give the minimum conditions for a behaviour that must remain as free as possible.
[14]The New Babylon project consisted of a series of models, constructions, maquettes, collages, drawings, graphics and texts expressing Constant's theories of urban development and social interaction.
[15] Because he lacked room to store the vast collection of constructions, maquettes, maps and structures he sold them all to the museum.
[8] However, more and more, he was inspired by contemporary and political issues, including such things as the Vietnam War, African famine and Kosovo refugees.
"[16] In the tradition of the Venetian Renaissance painters, Titian and Tintoretto, Constant applied himself to the technique of colorism.
Following this technique the artist doesn't make use of charcoal or pencil sketches but applies colour directly on the canvas with the paintbrush, constructing soft transitions instead of sharp contours.
For almost three decades the structure adorned the entry in anonymity until Rita Doets, a former employee of the municipality, left money in her legacy to construct an information sign next to the gate.
One by one he puts parts of the structures in motion and films the details with colored lighting having them overlap each other, appear and disappear.
They followed him and his dog, Tikus, on their daily stroll to the artist's studio, where he finished his last painting Le Piège.