The 1st rugby match was at Nelson 1870.
The game rapidly grew in strength. In 1906 the All-Blacks had a successful tour of Great Britain.
The premier professional competition is the ITM Cup. Played since 2006, currently 14 teams.
The reigning champions (2013) are Canterbury, who have won all but twice, the others being Auckland and Waikato.
See Wikipedia article for more details.
NZ has 5 teams in the Super League, along with 5 from Oz and 5 from South Africa.
2014 Super 15 : Waratahs b. Christchurch Crusaders by 1 point.
In the Women's World Cup held in France in (northern) summer 2014, there was shock as NZ was eliminated in the group stage; having been beaten by Ireland.
This was their 1st defeat since 2001 in the World Cup. Oz were also told to pack their bags. So things weren't entirely bad.
(The semi-finalists are France, Britain, ireland and Canada)