John Bathgate was born on 10 August 1809 at Edinburgh, Scotland, the son of Frances Hamilton Macdowall and her husband, Alexander Bathgate. His father had been a skinner, but rose to become a teacher in the day school at Peebles. Because John's mother had died when he was five, he was raised by his father and his second wife, Janet Campbell. After education at the Royal High School and the University of Edinburgh, Bathgate joined his father at Peebles as the assistant teacher. He then taught himself land surveying, worked in an estate office and, after a token apprenticeship and footing the bill for a sumptuous supper for his examiners, was admitted as a writer (solicitor) in 1835.
Over the next 28 years Bathgate took every opportunity that came his way. From his first professional task – administering a poor fund – he never declined a post, no matter how onerous the duties or how poor the remuneration. Alongside such roles as secretary of the Peeblesshire Prison Board, procurator fiscal and town clerk, he founded a newspaper, the Peeblesshire Monthly Advertiser and Tweedshire Journal, pioneered a private railroad from Edinburgh to Peebles, founded the Peeblesshire Savings Investment Society, and managed the Peebles branch of the Union Bank of Scotland.
Bathgate conducted his diverse affairs to the detriment of his health and the neglect of his family. On 6 April 1842 he had married Anne Cairns Anderson at Edinburgh; they had two daughters and two sons before Anne Bathgate died in 1851 shortly after the premature birth of a son, who survived only briefly.
When the British backers of the new Bank of Otago were looking for a colonial manager in 1863, Bathgate's name was put forward. He accepted the position and within a few months had left Scotland for Dunedin, New Zealand, accompanied by his four eldest children, his second wife, Mary McLaren, whom he had married at Edinburgh on 14 July 1853, and their six daughters; another daughter and a son were born in New Zealand.
Bathgate threw himself into his new role, which took him throughout Otago and Southland, but despite its demands he found time for other interests. As chairman of the newly formed Dunedin Water Works Company he travelled to Auckland to be on hand as the company's private bill went through the legislature. He became acquainted with Otago's parliamentarians, and in 1865, when the provincial government dismissed the Dunedin Town Board, Bathgate was installed as chief commissioner until new elections could be held.
Following a financial panic in London in 1866, there was a run on New Zealand banks. The Bank of Otago's business slumped and the London-based directors singled out Bathgate as the scapegoat. In October 1867 he agreed to resign on receipt of a consideration of £500. Having not long before purchased James Macandrew's 60-acre Carisbrook estate, which he had renamed The Glen, and taken on some expensive offices, such as a commission in the Otago Rifle Volunteers, Bathgate needed something to replace his £1,500 a year bank salary. Early in 1868 he became managing director of the Otago Daily Times, even acting as editor for a few months, though the salary was 'rather a downcome'. He followed this with an appointment as provisional trustee in bankruptcy and, his interest in law reawakened, he was admitted as a barrister and solicitor in 1870.
In late 1870 or early 1871 Bathgate was elected to the Otago Provincial Council and in June 1871 he joined the executive as provincial solicitor. Within a year he had been elected MHR for City of Dunedin. He joined the administrations of George Waterhouse and William Fox, briefly as commissioner of customs in 1872 and then as minister of justice and commissioner of stamps from 1872 to 1873.
Julius Vogel became premier in 1873, and Bathgate served as minister of justice and commissioner of stamps. As Vogel moved towards his decision to abolish provincial government, their relationship may have become uncomfortable. Bathgate remained an ardent parochialist, stridently urging separation for the South Island and even, at the conclusion of one impassioned speech, declaring his readiness to place himself at the head of his volunteer company and take possession of the custom-house. In February 1874 Vogel offered him the posts of resident magistrate in Dunedin and district judge for Otago. Already weary of the travelling a political career entailed, Bathgate accepted with alacrity and resigned from Parliament.
Bathgate prided himself on the work he put into his new role; indeed, in the next five years he took no holidays apart from statutory days such as Christmas. He kept meticulous notes and was reputed to have commenced every case by asking the prisoner where he or she was from, the smarter ones replying without hesitation, 'Scotland, Your Honour'. But Bathgate's other talents were not neglected. In 1875 he helped Thomas Bracken launch the Saturday Advertiser, even serving as its business manager until it was taken over in 1881, and founding the New Zealand Mortgage and Investment Association, of which he was managing director from 1881 to 1885.
In 1879 Bathgate applied for leave to visit Britain; on his promise to campaign in support of emigration to New Zealand, he was granted a year's leave on full pay. He was given a hearty welcome in Peebles, but after a short holiday set about justifying his leave. His friend William Chambers published Bathgate's paean to his adopted country, a book entitled New Zealand: its resources and prospects, and the author toured England and Scotland addressing packed public meetings. Bathgate had to answer over a thousand letters and his efforts resulted in New Zealand gaining migrants with a combined capital in excess of £100,000.
Once back in Dunedin Bathgate, now over 70, resigned from the Bench. Later newspaper accounts attributed his decision to increasing deafness, but neither this nor his age could keep him out of politics. In 1881 he won the Roslyn parliamentary seat only to lose it three years later to a better-organised opponent (Bathgate himself had always eschewed the use of any formal electoral organisation). Although happy to be free once more of the burden of travel, he nevertheless accepted an offer of a seat on the Legislative Council in 1885. He used his position to pursue his favourite causes: a state bank of issue to regulate the country's currency supply, curbs on the power of the public service, and stricter controls on the sale of liquor. The latter reflected his staunch membership of the Presbyterian church, of which he was an elder, and his active role in temperance societies. He died at Dunedin on 21 September 1886, survived by Mary Bathgate and all but one of his children.
John Bathgate's 23 years of service to private and public institutions in New Zealand drew deeply on his multiplicity of talents. He never regretted having made his home in 'a country where…there is no impediment in the way of ability taking any place to which its possessor desires to attain.'