(1756-1827) - Major
Commissioned: Cadet (HEIC - Bombay) 1775; Ensign 18 May 1775; Captain 10 June 1784; Major 6 May 1795; Lieutenant-Colonel 1 June 1796; Colonel 18 December 1803; Major-General 25 July 1810; Lieutenant-General 4 June 1814.
Born: 11 July 1756, at Exeter, second son of Lieutenant-Colonel Hildebrand Oakes (1733-1797), and Sarah [nee Cornelison] (d.1775).
Went out to India in 1775 as a Cadet in the East India Company and served with the Bombay army in Gujarat (1775-1776), Poona (1778) and at the sieges of Tellicherry, Onore, Mangalore, and Bednur (1780-1781). He was captured at Bednur in 1783 and made a prisoner of Tipu Sultan until 1784. After his release he served firstly with the 2nd Bombay European Regiment, and later, the 12th Bombay Native Infantry (until 1791) - taking part in several sieges and campaigns in 1791, including Cannanore and Seringapatam.
After 1790 Oakes served with his regiment in Bombay as Quartermaster-General and later as Commissary of Supplies, and undoubtedly it was in this capacity that Lachlan Macquarie first made his acquaintance with Oakes. In October 1792 Oakes was appointed deputy-adjutant-general of the Bombay army; whilst one month earlier, on 9 September, he married in Bombay Dorothea Bowles, daughter of General George Bowles. Later there would be six children from their marriage: four sons and two daughters.
Oakes gained promotion to Major 6 May 1795 and in 1796 received the title of adjutant-general with the Bombay army. It was in this context that Lachlan Macquarie left his young wife, Jane, in the care of Henry and Dorothea Oakes, while he participated in the military campiagn to Ceylon in early 1796. They would have witnessed first-hand Jane's declining health (from tuberculosis), advised Macquarie on his return from Ceylon and prior to his departure with her for China, as well as counselling him following his return (with his wife's body). They attended her burial in Bombay on 16 January 1797.
Oakes returned to Britain in 1798 on sick leave but went back again to Bombay in 1802 and became Colonel of the 7th Bombay Native Infantry. Ill health again forced him to return but he was back in Bombay again in 1807 as military-auditor-general. It is unclear the precise periods of overlapping residence (in Bombay) between the Oakes and Macquarie during the years 1797-1807 - though clearly their paths must have crossed on a number of occasions.
Oakes and his family returned to Britain soon after 1807. He was promoted Major-General on 25 July 1810, and Lieutenant-General on 4 June 1814. In 1822, following the death of his older brother, Hildebrand (1754-1822), Henry succeeded to his brother's [recent] baronetcy (1820). However, ill health plagued Henry Oakes' latter years and these were also complicated by bouts of insanity - culminating on 1 November 1827 with his suicide (by pistol). His wife, Dorothea, died on 24 May 1837.