Little is known about the career of Prince Hubertus. He received a private education before enrolling at the Gymnasium Casimirianum in Coburg. He then studied law. According to Harald Sandner, biographer of Duke Charles Edward, it became evident during the studies that Prince Hubertus was homosexual, but his sexual orientation remained secret. When his brother Hereditary Johann Leopold renounced his succession rights in order to marry a commoner in 1932, Hubertus became the new heir apparent to the defunct throne of Saxe-Coburg and Gotha. The same year, Hubertus attended the wedding of his sister Sibylla and Prince Gustaf Adolf of Sweden, Duke of Västerbotten, staying close to the bride during the ceremony. Hubertus himself was not willing to marry.
The father of Prince Hubertus, Duke Charles Edward, was an ardent supporter of Adolf Hitler. The entire family enthusiastically welcomed the rise of German nationalism. Soon, however, Hubertus and his mother, Duchess Victoria Adelaide, grew to despise the rising Nazi Party. After witnessing the torture of Jews, Prince Hubertus was forbidden to discuss it at home. The Second World War broke out in September 1939, and all of Charles Edward's sons were enlisted in the German Army. Prince Hubertus formally became a member of the Nazi Party on 19 October 1939, but remained opposed to Hitler for the rest of his life. In 1940, Hitler issued the Prinzenerlass, a decree prohibiting members of Germany's formerly reigning families from actively serving in the Wehrmacht, fearing that this would increase the public's sympathy for the deposed dynasties and threaten his grip on power. Such was Charles Edward's loyalty to Hitler, however, that the decree did not apply to the Duke's sons. During the war it was even reported that Hitler considered making Hubertus his Gauleiter for the United Kingdom. Prince Hubertus was an accomplished aviator. Serving in the Luftwaffe as a courier pilot in the Eastern Front, Hubertus obtained the rank of Oberleutnant. He was killed in action when his plane was shot down by the Soviet Air Forces on 26 November 1943 in Mosty, modern-day Ukraine. It was his last flight before he was to be relocated. News of his death spread on 3 December. Hubertus was buried the following day at the Coburg family cemetery at Callenberg Castle. The Duke and Duchess of Saxe-Coburg and Gotha announced the death of their son and heir in Gothaer Beobachter with a very short obituary on 11 December. The ducal couple's youngest son, Prince Friedrich Josias, became heir apparent in his stead. Princess Sibylla was distraught by the death of her favourite brother. In 1946, she had a son, the long-awaited heir to the Swedish throne, and named him Carl Gustaf Folke Hubertus; he later became King Carl XVI Gustaf of Sweden. When King Carl XVI Gustaf's grandson was christened Alexander Erik Hubertus Bertil, the choice of the name Hubertus was criticized by journalist Henrik Arnstad due to Prince Hubertus' membership of the Nazi Party. Arnstad was rebuked for his comments by political analyst Ivar Arpi.
