The Mitre 10 Cup, formerly the NPC (National Provincial Championship), is New Zealand's premier domestic competition and is generally played between August and October every year.
Originally featuring twenty seven teams, each representing a provincial union, this made up the competition across three divisions, which lasted until 2005.
In 2006 the Mitre 10 Cup (at the time the Air New Zealand Cup) was introduced, with the format evolving throughout the years.
The most recent version of the tournament – with the Premiership and Championship playing across two divisions – has been in place since 2011.
With the top 14 unions in New Zealand Rugby featuring in the Mitre 10 Cup, the remaining 12 play in the Mitre 10 Heartland Championship.
New Zealand's current provincial unions are (from north to south): Northland, North Harbour, Auckland, Counties Manukau, Thames Valley, Waikato, Bay of Plenty, East Coast, Poverty Bay, Hawke's Bay, King Country, Taranaki, Manawatu, Wanganui, Waiararapa-Bush, Horowhenua-Kapiti, Wellington, Tasman, Buller, West Coast, Canterbury, Mid Canterbury, South Canterbury, North Otago, Otago and Southland.
The NPC (now Mitre 10 Cup) has been contested since 1976, but has changed in format since then.
In the first year, Division One comprised seven North Island teams and four from the South Island, with the remaining provinces contesting a split second division, where South Island teams played each other and North Island teams did the same. The lowest-placed Division One team (South Island) played the winner of Division Two (South Island) in a promotion / relegation battle, thus keeping four South Island teams in Division One.
The format continued until 1985 when Division Three was introduced, split between islands in the same way.
The bottom-placed team was relegated automatically from Divisions One and Two, and the winner of Division Two was automatically promoted. The two winners from each island section of Division Three played off for promotion, which led to North Harbour's promotion to Division Two only a year after the union was formed.
Alongside the provincial competition, and between teams from different divisions, another trophy is on offer. In 1902 the governor of New Zealand, the fifth Earl of Ranfurly, presented a Shield to Auckland, who were undefeated in provincial competition that year.
And then the Ranfurly Shield was born, with Waikato the current holders.