Birthplace:
- Chawton, County Hants, England

Birthdate:
- 6 March 1848

Nationality:
- English

Height:
- 5 feet 9 1/2 inches

Family Background:
- Knight's father was Edward Knight, a landowner in, and Deputy Lieutenant, Justice of the Peace, and High Sheriff of county Hants

At Sandhurst:
- No

Foreign Languages:
- French

Career before Halifax:
- Ensign, 9 March 1867 (purchase)

Postings while in NS Command:
- Halifax, 3 June 1871 to 25 November 1871

Career after Halifax:
- Lieutenant, 24 July 1869 (purchase)
- Adjutant, 26 July 1877
- Captain, 27 March 1878
- Major, 27 March 1883
- Lieutenant Colonel, 1st Batallion, Seaforth Highlanders, 1 April 1895
- retired, 2 July 1895

Died:
- 27 February 1896

Henry John Knight's father, Edward Knight, was the eldest son of another Edward Knight. The latter had been born Edward Austen, and one of his sisters was the novelist Jane Austen. As a boy Edward Austen had been befriended by the very rich and childless Thomas Knight and his wife, the owners of the Godmersham Park and Chawton Estates. Eventually he was adopted by the Knights, assumed their name, and became their heir. After Edward came into possession of Godmersham in 1797 Jane Austen became a frequent visitor, and doubtless her experiences there influenced her depiction of English country house life in her novels. In 1809 Jane Austen moved into a cottage on the property of Edward Knight's other estate, Chawton, where she continued to live until her death in 1817, and at which she wrote most of her novels. Edward Knight (né Austen) died in 1843, and left his estate to his eldest son, Edward, whose third son was Henry John Knight, later of the 78th. Thus Henry John was born into the world of the wealthier segment of the English landed gentry, and could count as a poorer forbear one of the greatest English novelists.

Henry John Knight's first wish was for a commission in the 72nd Highlanders, but this evidently could not be arranged, and he took one in the 78th instead. Interestingly, after serving in the 78th for 28 years, he achieved his original wish in April 1895, when he became lieutenant colonel of the 1st Battalion Seaforth Highlanders, which formerly was the 72nd. He served in this position only briefly, however, before retiring in July 1895.