In July 1863 the Crown launched a premeditated war of conquest and invasion directed against Kīngitanga supporters in Waikato and their relatives living further north, around the shores of Manukau Harbour, at Ihumātao, Māngere and elsewhere. These were the same Māori communities who had been feeding and protecting the settlers of Auckland for more than two decades. Earlier, during the Northern War of 1845-46, they had pledged to defend the township from possible attack. But now they stood accused by the Crown of plotting to massacre these very same Pākehā. It was a desperate lie, attempting to justify the unjustifiable – the Crown levying war upon its own subjects. 

Those allegations were not only entirely unfounded but also illogical. Destroying the key outlet for their produce would have been suicidal for the Māori communities concerned. Their wealth and therefore power depended to a large degree on Auckland’s ongoing well-being. It was a mutually beneficial relationship – at least until Governor George Grey decided that the Kīngitanga had to be destroyed, paving the way for the invasion of its Waikato heartland in July 1863. 

As part of Grey’s preparations, Tainui communities living around the Manukau Harbour and elsewhere were forcibly driven from their lands.  On 9 July 1863 a proclamation was issued by the government addressed to 'the natives of Mangere, Pukaki, Thirmatao [sic - Ihumatao], Te Kirikiri, Patumahoe, Pokeno, and Tuakau', warning that:

All persons of the native race living in the Manukau district and the Waikato frontier are hereby required immediately to take the oath of allegiance to Her Majesty the Queen, and to give up their arms to an officer appointed by Government for that purpose.

Natives who comply with this order will be protected. Natives refusing to do so are hereby warned forthwith to leave the district aforesaid, and retire to Waikato beyond Mangatawhiri. 

In case of their not complying with this order they will be ejected.