In a 1985 interview, Samy said that his brother Jonas taught him chess when he was ten years old. Jonas was nine years older than him. His father had retired from the game in 1931.
In 1943, deportations in Nazi-occupied Belgium began and he fled with his mother into the Wallonian countryside. While his father stayed hidden in a hospital in Brussels and Jonas went into hiding in Brussels, they found a shelter in a castle in the Ardennes with other Jewish refugees. In the fall of 1943 the castle was raided by the Nazis and everyone was arrested. His mother, however, managed to escape. Samy survived a year in the concentration camp of Mechelen/Malines doing forced labor. He was liberated by British troops in September 1944 and the Rubinstein family reunited. That was when Samy became more interested in chess. He joined a chess club and played in Belgian tournaments from 1948 onward.
I had always thought his father, Akiba, was not much more than a vegetable, but that was not the case. Although Akiba remained withdrawn and lived mostly in his room, he did receive visitors, read the papers and kept up with chess. Samy practiced with his father (see more on Akiba and chess below) and became champion of Brussels in March 1949. Later that year Samy went to the United States where he played at the Marshall Chess Club in New York. He returned to Belgium in 1951 and studied art at the École des Beaux.
In 1954 his mother his mother died and he spent three years in a psychiatric institution. However, he returned to tournament play in 1956 and became a member of the CREB (Cercle Royale des Échecs de Bruxelles), winning the CREB championship many times. CREB magazine later reported him to be a very good rapid player.
Rubinstein also lived in the Netherlands at some point where he won the Amersfoort Championship. In his later years, he was a regular at chess tournaments in Brussels. In 1980 and 1985 he won the Championnat individuel de la Francophonie. He was noted for his speed of play, often using less than half an hour for the entire game. His last FIDE rating was 2380.
He painted Bronstein’s portrait for Tom Furstenberg’s book The Sorcerer’s Apprentice. He died in Brussels, aged 75.
I might add that Akiba Rubinstein retired from chess in the early 1930's and lived out his life in isolation suffering from anthropophobia (a fear of people) and traces of schizophrenia (abnormal social behavior and failure to recognize what is real), but, as mentioned above, that did not mean he was out of touch with chess. In his autobiography Chess the Hard Way, Abe Yanofsky wrote, “From Copenhagen, I traveled to Amsterdam to pick up my remaining luggage at the Keesing's homes, and early in February (of 1947) I started on my journey back to Canada via Brussels, England, and Iceland. In Brussels, I was introduced to the veteran Akiba Rubinstein, whom I found to be looking fit and not so old. We sat down to play a skittle game in his home, but we soon became so absorbed in the game that it stretched out to 3½ hours and proved to be as tough as any tournament game I ever played." Also, Samy recalled how he and his father analyzed games from the 1957 Smyslov vs. Botvinnik match for the world championship. Chessgamesdotcom has a number of training games played between father and son.
Also of interest on YouTube is
Rubinstein and Polish Chess – Part 1
Rubinstein and Polish Chess – Part 2
Rubinstein and Polish Chess - Part 3
The Boylston Chess Club has an interesting page on the history of the Rubinstein family in photos.
In this game his opponent, Josef Boey (born May-16-1934 in Antwerp) was awarded the IM title in 1973 and the Correspondence Grandmaster title in 1975 as a result of his second place finish in the World Correspondence Championship. The opening is one of the most complicated in chess and the end of the game is rally messy with a lot of tactical errors. Some no doubt were the result of time pressure and a couple were, I think, only moves that could be seen by an engine.