George Stoddart Whitmore (1829-1903) had the military in his blood most of his life, and he first fought for the British in South Africa from 1847-1853.
He returned to his homeland England, before serving in the Crimean War in 1856 - where he distinguished himself in dispatches fighting the Russians.
In 1861, he was sent to New Zealand as a military secretary, but upon arriving, the hostilities with Maori had ended, which led to him eventually resigning his commission in 1862. And as James Belich said, his promising military career had come to a halt. Whitmore had purchased a farm near Napier in 1861, which he called Rissington, so he left Auckland to farm in November 1862.
As fate would have it, when unrest from Maori in the Waikato region occurred in 1863, Whitmore took the rank of Major, and organised the Napier Militia.
After returning from a visit to England in 1866, he was given the title of Lieutenant-Colonel by the government, and returned to active military service under threat of an invasion from the Hauhau tribe. When the Hauhaus did invade, George Whitmore commanded the Napier Militia against them at the Battle of Omaranui in October 1866.