Birthplace:
- Ferrintosh, Ross-shire

Birthdate:
- 1 March 1837

Nationality
- Scottish

Height:
- 6 feet 2 inches

Family Background:
- His father was referred to as "Forbes of Haddo", but apart from this nothing is known

At Sandhurst:
- No

Foreign Languages:
- None

Career before Halifax:
- Ensign, 19th Foot, 12 January 1855 (purchase)
- Lieutenant, 10 July 1855 (non purchase)
- Captain, 24 May 1859 (purchase)
- to 78th Highlanders by exchange, 15 January 1861

Medals & Awards:
- Medal and clasp (Crimea)
- Turkish Medal

Postings while in NS Command:
- in Scotland until 19 May 1871
- to Halifax, 20 May 1871

Married:
- Ann Winlock, at Presbyterian Church, Drummoch [?] 18 May 1869

Career after Halifax:
- Brevet Major, 5 July 1872
- Major, 11 July 1877
- Brevet Lieutenant Colonel, 8 November 1880
- Lieutenant Colonel, 1 July 1881
- Colonel, 8 November 1884

Died:
- 29 December 1881

Forbes was in Halifax for only the last six months of the 78th's posting here. Before that he was in charge of the depot company in Aberdeen, Scotland. He was in Halifax long enough to became involved in the activities of the local North British Society, and was one of the organizers of the celebrations which were held to commemorate the centenary of the birth of Sir Walter Scott of 15 August 1871. 

In March 1883 Forbes succeeded Augustus Warren as the regiment's commanding officer. He held this position until his untimely death at Netley Military Hospital in Ireland on 26 December 1884.