Alexander Don was born in a tent at Ballarat, Victoria, Australia, on 22 January 1857, the eldest of the 10 children of John Don, a goldminer, and his wife, Janet Nicol. Both parents came from Scotland where his father was a stonemason who contracted for bridges and culverts.
Although Alexander showed an early aptitude for learning, he left school at the age of nine to work on his grandfather's farm. He then undertook prop-cutting and foundry work and spent three years stamper-feeding at a mining battery. However, he also attended night classes and his teacher was so impressed with his capability that he persuaded Don's father to let the lad return to school. At 15 Don became a pupil-teacher, and he qualified as a teacher at 21. He was already noted for methodical attention to detail.
Don expressed a wish to become a missionary and was advised to seek the New Hebrides (Vanuatu) post offered by the Presbyterian Church of Otago and Southland. Arriving in Dunedin, New Zealand, in January 1879, Don found the post filled but accepted the alternative position of Presbyterian missionary to the region's Chinese gold-seekers. He was sent to Canton (Guangzhou), where he learnt Cantonese in close co-operation with the American Presbyterian mission.
Returning to Dunedin in 1881, Don commenced theological training. In 1882 he was stationed in Riverton, Southland, on a salary of £300, to proselytise the 500 Chinese at the nearby Round Hill goldfield. There, in 1883, he opened the first Chinese mission church in New Zealand. On 14 April the same year, at Warepa, near Balclutha, he married his American fiancée Amelia Ann Warne (known as Millie), whom he had met in Bendigo, Australia. They were to have seven children. The mission failed to prosper as Don unwisely involved himself in local disputes. In 1886 he was transferred to Lawrence, where he was ordained later in the year. There were again some 500 Chinese in his area, which included the Tuapeka goldfield, but Don made little positive impact; on Chinese New Year 1888 only one Chinese called on him. Instructed to undertake inland circuits of the Chinese, he started his annual summer preaching tours. In the course of these he was eventually to cover some 16,000 miles on foot.
From 1889 Don was based in Dunedin. By 1895 he appeared to understand the Chinese language better, and in 1897 he opened the Chinese Mission Church in Walker Street (Carroll Street) to cater for a small Chinese congregation. In the late 1890s Don conceived the idea of founding a Presbyterian mission in the upper Panyu district (where most of the Otago Chinese originated) just north of Canton, and linking it to his own New Zealand mission. In 1897 he went back to Canton to reconnoitre the district and was again welcomed by the American Presbyterian mission, which offered to help a fledgeling New Zealand mission. He also had the toleration, if not the active support, of families of men who had returned from New Zealand. This was the beginning of the Canton Villages Mission. Don set about fund-raising for the new mission, and following his return to New Zealand travelled extensively to publicise it. He also helped Chinese with immigration problems and remittances. He launched a successful appeal among Europeans in 1907 for famine relief in China, raising over £2,600; as a token of gratitude for this and a later famine fund, in 1924 the Chinese government conferred on him the Seventh Council Insignia of the Excellent Crop. As moderator of the General Assembly of the Presbyterian Church of New Zealand in 1907–8, Don stressed the importance of missions, and successfully called for a mission to India.
Helped by a succession of three Chinese assistants, Alexander Don had attracted a Chinese congregation of over 50 to his Dunedin mission church by late 1909. Unfortunately the insensitivity he too often displayed led to a fall in numbers and consequently Don shifted to Palmerston North in 1913. He was called back to Dunedin in December to take up the new position of Presbyterian foreign missions secretary, which he filled with distinction. He encouraged the missionaries to write about their work, and himself wrote Light in dark isles on the New Hebrides mission. In 1923 Don retired to Ophir, Central Otago. Here he kept meteorological records and wrote a biography of Peter Milne, the first missionary sent by the Presbyterian Church of Otago and Southland to the New Hebrides, and his major book, Memories of the golden road: a history of the Presbyterian church in Central Otago. When bearing the latter manuscript to his publishers on 2 November 1934 he died on the train near Ranfurly; the manuscript was lost, and was later painstakingly reconstructed by his son-in-law, William Bennett. Amelia Don, who had assisted her husband in his mission work, died on 20 March 1937.
Don had limited success as a missionary and baptised only about 20 Chinese, a quarter of whom were converted by others. He was careful of the image he presented to Europeans, but to Chinese he displayed an uncompromising, overbearing attitude, and betrayed confidences in his prolific writings. He never entirely lost his prejudice towards them. Particularly during periods of mental distress he made sweeping critical statements – for example, 'it is very hard to say anything positively about a Chinese' – which his superiors appear to have condoned. In turn, the Chinese leadership in Otago and Southland, and at first the majority of the Chinese, appear to have ignored or spurned Don. In later years attitudes softened on both sides, but the Presbyterian mission never achieved integration with the Chinese community.
Don's writings nevertheless form the chief source of our knowledge of the New Zealand Chinese in this period. His three surviving diaries, loose papers, numerous articles and reports of his annual tours and second trip to China, the unique bilingual roll of Chinese in New Zealand from 1883 to 1913, and his wonderful collection of photographs combine to form a cache of information about the Chinese gold-seekers of last century unmatched in any other country.
To Europeans Don seemed zealous and tenacious; a man of great physical endurance and dedication, an untiring fund-raiser and excellent organiser, a skilful, meticulous author of church history, and a blameless family man. He won widespread approbation from European Presbyterians. If he had strictly limited success as a missionary, he nevertheless gave an impetus to the wider missionary movement within the Presbyterian church.