Henry was a son of Frederick William II of Prussia (1744-1797) by his second wife Frederika Louisa (1751-1805), daughter of Louis IX, Landgrave of Hesse-Darmstadt.

Henry entered the army on 5 September 1795 as a fähnrich in the Life Company of the 1st Guards Battalion.

[1] On its dissolution, Henry's brother Frederick William III of Prussia set up the Royal Prussian Order of Saint John with Augustus as its Grand Master.

Under Henry the new Order set up a hospital in Jüterbog and a 'Deaconess Institute' (Diakonissenanstalt) in Bucharest.

On 12 August 1817 Henry visited the USS Washington during her time as the US flagship in the Mediterranean.