Mahraraja Hari Singh was born on 23 September 1895 at the palace of Amar Mahal, Jammu, the only surviving son of Raja Amar Singh Jamwal, the brother of Maharaja Pratap Singh, then the Maharaja of Jammu and Kashmir. Since the Maharaja had no issue, Hari Singh was heir to the throne of Jammu and Kashmir.
In 1903, Hari Singh served as a page of honour to Lord Curzon at the grand Delhi Durbar. At the age of thirteen, he was sent to Mayo College in Ajmer. A year later, in 1909, his father died, and the British took a keen interest in his education and appointed Major H. K. Brar as his guardian. After Mayo College, Hari Singh went to the British-run Imperial Cadet Corps at Dehra Dun for military training.
Maharaja Pratap Singh appointed him as the commander-in-chief of the State Forces in 1915.
He was married four times. With his fourth wife, Maharani Tara Devi (1910–1967), he had one son, Yuvraj (crown prince) Karan Singh.
