Christchurch is the largest city in the South Island of New Zealand and the third largest city in the country. It is a coastal city, situated in the middle of the South Island's east coast just north of Banks Peninsula.
The city is named after its eponymous cathedral, which is itself named after Christ Church, a college at the University of Oxford, and simultaneously the Cathedral of Oxford. The city was originally known as Christ Church, the name being abbreviated through common usage by the 1880s.
The usual Māori name Ōtautahi is a shortened form of Te Whenua o Te Potiki-Tautahi - named for the seasonal dwelling of Ngai Tahu chief Tautahi of Port Levy on a bank of the Avon River near to where the Barbadoes Street bridge now stands.
Description courtesy of Wikipedia