This should probably be in the simple questions thread. New Zealand was discovered by Dutch explorers in the 17th century, specifically Abel Tasman, who named it Staaten Land, after the States General of the Netherland. It was later renamed by Dutch cartographers as New Zealand, after the Dutch province of Zeeland, but the Dutch never settled on the islands. British explorer James Cook first mapped the islands in the late 18th century, and British colonization (that is European colonization more generally) didn't begin until the 19th century. So by the time New Zealand ever began as a colony, it had already had that name for about 200 years.

Not sure how to source this really. This is what is generally considered general knowledge.