The Invasion of the Waikato became the largest and most important campaign of the 19th-century New Zealand Wars. Hostilities took place in the North Island of New Zealand between the military forces of the colonial government and a federation of Māori tribes known as the Kingitanga Movement. The Waikato is a territorial region with a northern boundary somewhat south of the present-day city of Auckland. The campaign lasted for nine months, from July 1863 to April 1864. The invasion was aimed at crushing Kingite power and also at driving Waikato Māori from their territory in readiness for occupation and settlement by European colonists. The campaign was fought by a peak of about 14,000 Imperial and colonial troops and about 4,000 Māori warriors drawn from more than half the major North Island tribal groups.

The New Zealand Wars took place from 1845 to 1872 between the New Zealand colonial government and allied Māori on one side, and Māori and Māori-allied settlers on the other. They were previously commonly referred to as the Land Wars or the Māori Wars, while Māori language names for the conflicts included Ngā pakanga o Aotearoa and Te riri Pākehā. Historian James Belich popularised the name "New Zealand Wars" in the 1980s, although according to Vincent O'Malley, the term was first used by historian James Cowan in the 1920s.