Dunedin's relationship with Edinburgh has obvious historical links, not least the 1843 decision to name the New Zealand Company's new Scottish settlement Dunedin, the Gaelic form of Edinburgh.
The first movement towards creating an official link with Dunedin's historical 'sister' was in February 1973, when the Scottish Export Committee of Dunedin's Scottish Council recommended that a 'twinning' relationship with Edinburgh be formalised. [...]
[...] A formal resolution confirming the establishment of an official sister city relationship was exchanged on 1 July 1974, with a copy of the formal resolution presented to the Lord Provost in Edinburgh by Cr M Joel on 25 July 1974.
@ http://www.dunedin.govt.nz/your-council/sister-cities/edinburgh