Three years younger than his older brother, Wilhelm, who was second in the line of succession after his father, Heinrich opted to join the navy when he was fifteen and he embarked on a two year voyage around the world. The prince rose quickly through the ranks, mainly due to his royal birth, and he became the first European aristocrat to be received at the Chinese imperial court. Heinrich was a Grand Admiral by the time the First World War broke out and was named Commander-in-Chief of the Baltic Fleet.
On 24 May 1888, Heinrich married his first cousin, Irene of Hesse and by Rhine, and they had three sons: Waldemar (born in 1889), Sigismund (born in 1896), and Heinrich (born in 1900). Sadly, Waldemar and Heinrich were both haemophiliacs, a disease inherited through Irene from Queen Victoria. Heinrich and Irene’s mothers were both daughters of Queen Victoria but their grandmother was displeased by their marriage as she had not been aware of their courtship. Heinrich and Irene had a fairly happy marriage though and most people who met them liked them.
When his brother became German Emperor, Heinrich did not have a significant role at court but he did act as his older brother’s representative when the occasion called for it until Wilhelm’s eldest son was old enough to take over. Heinrich was not really interested in politics and he would never have thought of opposing his brother’s policies. The First World War was tough on Heinrich’s wife, Irene, as she found herself on the opposite side from her sister, Alix and Elisabeth, who had married into the Russian imperial family. Irene was distraught when she learned they had all been murdered by the Bolsheviks.
After the war ended, Heinrich and Irene were allowed to resume living at Hemmelmark, in northern Germany, where Heinrich died of throat cancer, like his father, on 20 April 1929.