Mark was the son of James Brownlow and Mary Brownlow nee Holdroyd.
According to the information they provided on the 1911 Census, James and Mary had been married for 38 years and had had 11 children of whom 10 were still living at the time of the census. However, only nine children were named on the census between 1891 and 1911; Thomas (b. 1875), Eliza (b. 1878), Wallace (b. 1880), Mark (b. 1881), George (b. 1886), Arthur (b. 1888), Annie (b. 1890), Alfred (b. 1893) and Frederick (b. 1898). All the children were born in Nottingham.
In 1891 the family was living at 25 Mount Pleasant, Basford. James was a coal miner. Seven children were at home on the night of the census; Thomas (15), a lacemaker, Eliza (13), Wallace (10), Mark (9), George (5), Arthur (2) and Annie (1). Also in the household were James' parents-in-law, William Holdroyd (71) a framework knitter) and Eliza Holdroyd (72).
By 1901 the family was living at 70 Bailey Street, Basford. Seven children were still at home; Thomas (25) a lace warehouseman, Wallace (20) a hosiery bleacher), Mark (19) a mechanical engineer, George (15), Annie (11), Alfred (7) and Frederick (2). William Holroyd (82) was still living with the family.
On 27 August 1903 James' eldest son, Thomas, married Ellen Brown at the Methodist New Conection Chapel, Nottingham.
In October the same year Mark joined the Royal Navy and by the time of the 1911 Census was serving at HMS Mercury, Portsmouth, although on the night of the census he was a visitor in the home of Frederick Hobbs, an engine fitter, at 54 Edmund Road, Southsea, Hampshire.
By 1911 Mark's parents had moved to 65 Vernon Avenue, Old Basford; only George (25) a coal miner, Annie (21) a lace finisher/machinst) and Frederick (12) were still at home.
Alfred (18) had already joined the Royal Field Artillery and was in Lille Barracks, Marlborough Lines, Aldershot, with the 116th Battery. Alfred married Minnie Newton in 1912; she later married Sam Taylor (1920).
Arthur (22), a twist hand (lace maker), was a boarder at 12 Park Street, Heanor, in the household of William (60) and Jane Holdroyd (60), who may have been related to Arthur's mother.
Wallace Brownlow (30) a hosiery bleacher, was living at 53 Springfield Street, Basford, with his wife of 5 years, Agnes (28), and their son Mark (2). Wallace died on 16 June 1955 aged 74.
Thomas and Ellen Brownlow who were married in 1903 were living at 137 Vernon Road, Basford.
Mark's brother 62210 Bombadier Alfred Brownlow joined the Royal Field Artillery before the war and was killed in action on 24 March 1918 serving with the 71st Battery, 36th Brigade (Arras Memorial). He was 25 years old. Their brother, Thomas, attested in December 1915 when he was 40 years 5 months old, and was transferred to the Army Reserve on 10 December 1915 (155655 Private, RAMC). He was not mobilized until 12 July 1918; he was demobilized on 9 March 1919 to 137 Vernon Avenue, Old Basford.