Charles Ewing Mackay (later known as Charles Evan Mackay) was born in Nelson, New Zealand, on 29 June 1875, the son of Joseph Mackay and his wife, Jessie Wilkie. Joseph taught mathematics at Nelson College, and from 1881 to 1891 was headmaster of Wellington College. Charles was a pupil there from 1883 to 1890, then studied at Canterbury College on a Junior Scholarship. A brilliant student, he graduated BA in 1895 and LLB in 1900. He was called to the Bar in New Plymouth in 1901, and the following year established his own law firm in Whanganui. There on 20 January 1904 he married Isobel Mary Agnes Duncan, who was from a prominent Whanganui family; the couple had a daughter and a son.
Mackay entered local politics in 1904, serving first on the Mataongaonga Road Board and gaining election to the Wanganui Borough Council in November 1905. In April 1906 he successfully contested the mayoralty, holding office until 1913, and again from 1915 until 1920. He stood for Parliament as an independent candidate for Whanganui in the 1908 and 1911 elections; though unsuccessful, he remained popular in local affairs.
Mackay was a controversial and energetic mayor who was responsible for much of the growth and development of Whanganui in the years between 1906 and 1920. His projects were frequently expensive but always farsighted. He advocated the building of an electric tramway system for Whanganui, improved the town's roading, water supply and fire services, and was instrumental in having the Dublin Street Bridge erected. He ensured the incorporation of the outlying areas of Aramoho and Wanganui East within the borough boundaries, and worked continuously to encourage the development of the port and local industry.
His principal project from 1915 was the construction of an art gallery for Whanganui, using the bequest of Henry Sarjeant. He instigated a competition for the building's design (which was won by the Dunedin firm of Edmund Anscombe), promoted a purchasing policy for the gallery, wrote tirelessly to galleries and collectors abroad soliciting works and reproductions, and confronted the Department of Education over the acquisition of land for the site. He later persuaded the military authorities to defer the posting overseas of one of the architects, Donald Hosie, until the gallery's working drawings had been completed. Hosie was killed at Passchendaele (Passendale) in October 1917, three weeks after the foundation stone for the Sarjeant Gallery was laid.
During the First World War Mackay's popularity suffered in some quarters. He did not serve in the military forces, and his relations with the Wanganui Returned Soldiers' Association were to be less than cordial. The mutual hostility came to a head during preparations for the visit in 1920 of the prince of Wales, when Mackay opposed the RSA's plan to hold their own welcoming ceremony. The royal visit of 3 May took place in an atmosphere of considerable acrimony. Unperturbed, Mackay had turned his attention to promoting the construction of a library and museum to complement the gallery. He had also begun investigating the possibility of a power station for the borough. But his introduction to the writer Walter D'Arcy Cresswell on 10 May 1920 was to change his future prospects dramatically.
Cresswell was a returned soldier who had come from his home in Timaru to visit relatives near Whanganui. The two men became friendly and met on several occasions. On 15 May after an argument at his office Mackay shot and seriously wounded Cresswell. It was later alleged that Mackay had made homosexual advances to Cresswell, who then attempted to extract a letter of confession and resignation from the mayor. Cresswell stated that he had led Mackay on, 'to make sure of his dirty intentions'. Mackay was arrested and charged with attempted murder; he pleaded guilty, acknowledging the factual truth of an unsworn evidential statement that Cresswell made from his hospital bed. No defence was called, though a plea in mitigation was made when Mackay was sentenced to 15 years' imprisonment, which he began serving in Mount Eden prison.
After his imprisonment Mackay's wife petitioned for divorce and returned to her maiden name, the street called after him had its name changed, and reference to him was deleted from the foundation stone of the Sarjeant Gallery and not restored until 1985. His portrait was removed from the Borough Council chambers and destroyed. No mention of him or his services to Whanganui appeared in any local history for the next 50 years.
Charles Mackay was reportedly released from prison in August 1926 and went to England. By 1928 he was working as a journalist for the Sunday Express, possibly on the recommendation of the expatriate New Zealand writer Hector Bolitho. From later 1928 he was a correspondent in Berlin, and was covering the street battles between communist irregulars and the police in the Neukölln-Hermannplatz district when he was shot dead by a policeman – apparently as a result of a misunderstanding – on the night of 3 May 1929. The German foreign office expressed regret to his family, and his death was widely reported in New Zealand, though only brief mention was made of his earlier achievements.
The sensational nature of Mackay's disgrace in 1920 all but expunged from local history a career of considerable public service. The expansion of Whanganui's boundaries, its commercial and residential services, and its cultural facilities, came about largely through the efforts and influence of Charles Mackay.