[1] Nothomb earned a doctorate in law from the Université catholique de Louvain in 1957.

On 14 October 1953, Nothomb was granted the hereditary title of Baron for him and his family by King Baudouin.

[2] In 2012, he earned Luxembourgian nationality due to his family lineage prior to the division of Luxembourg in 1839.

[3] In his free time, Nothomb was a singer of the Japanese style Noh, and was a director of the Europalia festival in 2004 in Italy.

[4][5] Nothomb died on 17 March 2020 from a heart attack and also COVID-19 during the COVID-19 pandemic in Belgium.