From Henry Sewell in 1856 to Jacinda Ardern in 2017, Aotearoa New Zealand has had 40 prime ministers and premiers. In the 19th century these political cabinet-makers were usually known as ‘premiers’ but since 1906, beginning with William Hall-Jones, all the leaders of New Zealand have been sworn in as ‘prime minister’. Photograph : Michael Joseph Savage the first Labour Prime Minister of New ...