William Thomas Trethewey was born in Christchurch on 8 September 1892, the son of Cornish parents Mary Wallace and her husband, Jabez Trethewey, a carpenter. He left East Christchurch School at the age of 13 and began work as a wood carver of such objects as finials, fireplaces and bedheads. He studied under the noted Christchurch wood carver, Frederick Gurnsey, at the Canterbury College School of Art, and in 1914 studied life modelling under Joseph Ellis in Wellington. But essentially Trethewey was self-taught, learning anatomy by concentrating upon a different muscle each morning while he shaved, and sculpture through reading about Bernini, Michelangelo and Rodin. He began to see himself as following in that tradition and soon abandoned wood carving to become a monumental mason. Throughout his working life his bread and butter was provided by touching up marble angels imported from Italy and carving headstones for the people of Canterbury.
The need for war memorials at the end of the First World War offered Trethewey new opportunities. He produced a simple stone cross for Elmwood School, and then carved a highly realistic statue of a New Zealand soldier, 'The bomb-thrower', which he showed in the Canterbury Society of Arts exhibition in 1919 as a model for local war memorials. The work excited great interest and was purchased by the society, only to be lost. But most New Zealand communities preferred to memorialise the war dead in more traditional forms with mass-produced carvings imported from abroad. During these years Trethewey received only one war memorial commission, from the Kaiapoi community. Unveiled in 1922, it was a portrayal of a digger, exact in the details of the kit even to the broken bootlace, and with a face evocative of a muscular, determined, New Zealand soldier. It was judged at the time as the personification of the Anzac spirit. The base was prepared by Daniel Berry, a monumental mason whom Trethewey had joined in 1921, but in 1923 the partnership dissolved.
That same year saw the unveiling in Waimate of a life-sized sculpture of Margaret Cruickshank, the local doctor who had died in the influenza epidemic of 1918. Trethewey carved the statue (like the Kaiapoi memorial) out of a five-ton piece of marble imported from Carrara, Italy. He used photographs to capture a likeness that pleased Waimate people, and was paid £800 for the work.
Further commissions followed: a bust for the Christchurch Hospital of Hyam Marks, a benefactor; another of a former mayor, C. M. Gray, for the city council; a brawny New Zealand shearer for the New Zealand pavilion at the Wembley exhibition of 1924–25; and plaster work for the Civic Theatre in Christchurch. Then in 1928 Trethewey won a competition for his biggest commission yet, a sculpture of Captain James Cook, funded by a bookmaker, M. F. Barnett. Working with a 12-ton piece of Italian marble, he produced a heroic sculpture in the European tradition, which brought him considerable publicity, including coverage on Movietone News. The work was unveiled in Victoria Square in 1932.
By then George Gould, a prominent citizen, was advancing his plans for a large memorial to Canterbury's war dead to be sited in Cathedral Square. Although the original intention was to import statuary from England, a motion from the Canterbury Manufacturers' Association suggested a local artist. Gould had wanted a design that was an emblem of peace not war, and the cathedral chapter wished for the inclusion of a cross and an expression of high ideals.
Trethewey produced a design that satisfied these needs: a central cross, some 60 feet high, with six symbolic bronze figures at the base, and in the middle an angel breaking the sword of war. In June 1933 the design was accepted. It was to be four years before the memorial was unveiled. Trethewey refined the designs, reducing the number of figures to five (Youth, Justice, Peace, Valour and Sacrifice), then carved them full-size in clay, boxed and sent them to Burtons foundry in London for casting. He travelled to Britain in 1936 to supervise the process and spent several months seeing the art treasures of Europe. He was paid five shillings an hour for his work, plus a bonus of £500. In the completed memorial the figures are beautifully proportioned with lively individual faces, based on Trethewey's friends and family, and the balance of forces and proportions in the design is superb. Arguably this is the finest public memorial in the country.
Trethewey was also involved in other work in the 1930s: a sculpture of Maui Pomare, unveiled at Waitara in 1936; a large model of a muscular male torso proposed as a pioneer memorial; and then, in 1938–39, the statuary for the New Zealand Centennial Exhibition at Rongotai in Wellington. Working more swiftly in plaster, rather than his usual stone, he had the opportunity to turn New Zealand myth into sculpture. There was a large 100-foot frieze on the progress of New Zealand; two dramatic groupings (a pioneer man and son, and a pioneer woman and family); lions in art deco style, which stood outside the British pavilion; a decorative fountain; and the large figure of Kupe standing on the prow of his canoe. Sadly, of this work only the sculpture of Kupe survives.
Trethewey's sculpture brought neither fortune nor fame. His monumental realistic style became increasingly anachronistic, and after the Second World War New Zealanders were not interested in heroic stone memorials. There was one small commission for a bas-relief on the steps of the Nelson cathedral to commemorate the city's centennial in 1942, but in his later years Trethewey put much of his artistic energies into making clocks. He remained an active member of the Canterbury Society of Arts.
William Trethewey died in Christchurch on 4 May 1956. He was survived by his wife, Ivy Louisa Harper, whom he had married in Christchurch on 24 July 1914, and four children. One of his sons continued the family's monumental mason business, which has now been carried on to a third generation, keeping alive the Trethewey name. Trethewey was New Zealand's outstanding home-grown sculptor in the first half of the twentieth century, and because of his sculptural skills and commitment to New Zealand subjects he deserves to be better remembered.