In 1945 he was a founding member of the 'Jeune Peinture Belge' group. By the end of that decade he was briefly associated the CoBrA movement, publishing some of his art in the CoBrA magazine.
In 1950 he moved to New York. After a brief stay in Rome, he returned to the United States in 1956, becoming head of the Painting Department at the School of the Museum of Fine Arts.
Jan Cox was psychically hyper-sensitive and suffered from recurrent depression throughout his life, eventually leading to his suicide, in Antwerp, in 1980. He is buried in the Schoonselhof Cemetery in Antwerp.
Several of his paintings are abstract, though some of his major successes were with (partly) figurative work: for instance, the cycle based on the myth of Orpheus which he produced in Boston, the cycle based on Homer’s Iliad he produced after his return to Antwerp.
Jan Cox was convinced that the technical capabilities of a painter were of minor importance for the quality of the painting that resulted: in his view all technique a painter needed for the creation of paintings could be learnt in a few months, the rest depended on the painter's creativity.Wikipedia