 The North and South Island names arose through common usage rather than official declaration and in 2009 it was revealed that they had never been formalised.In 2013, alternative names were formalised for the two main islands, as North Island or Te Ika-a-Māui, and South Island or Te Waipounamu, with either English or Māori name being used or a combination of both.Many Māori place names possess either historical or mythological significance.