Thomas joined the 58th Rutlandshire Regiment on 8 Jan. 1842 (Reg No2148) and his Regiment was posted to New South Wales. They sailed for Hobart on the ship "William Jardine" on 01/07/44 arriving in Hobart on 20/11/44, from there on to Norfolk Island where they arrived on 05/12/45 - then to Auckland on 23/12/45.

The UK government had sent the regiment to assist in suppressing the uprisings of the Ngapuhi under Hone Heke and Kawiti in the far north. They saw action when they attacked Kawiti's Pah at Puketutu along with other English Regiments and then joined in the famous week long attack on Heke's Pah at Ruapekapeka (The Bats Nest) The attacking troops only succeeded in getting into the Pa on the Sunday whilst the warriors were at Divine Service outside the rear of the pah (January 1846)

Thomas after serving in other parts of the New Zealand Wars, took his discharge from 58th Regiment at Auckland on 22/11/1853 after a 9 year period of service and settled in Howick where the regiment had been based. The Fencibles were all ex Imperial troops who lived in the four Fencible Settlements on the then outskirts of Auckland. One was at Howick, the others at Onehunga, Panmure and Otahuhu. The settlements were to be part of a line of defence in the event of a Maori invasion from the South. The Fencibles were paid a small wage and were permitted to work within a five mile radius of their settlement. They were required to attend a weekly military parade and to maintain their uniform and rifle and each was given an acre of land and the materials to build a 2 room cottage.

Thomas worked as farmer, contractor etc doing a good deal of work for McLean and other well known colonists. In March 1855 Thomas Finch worked for 5 days for Mr Lynch in Feb 1855 at 6/8d per day and for 2 days at 7/4d per day.  On the days which he threshed, Mr Lynch agreed to pay more - 7/6d a day   He put up and fed Mr Lynch's horses on a Sunday when he started work at 8 am and left at 7 pm and fed and put horses away each night and morning. 

At the outbreak of the Waikato war at Penrose on 9 October 1863, he again enlisted "Thomas Finch, No. 1128;  Trade farmer; age 39 years; Size 5 ft 8 inches; Married with four children; ex-58th Regiment". He joined the Militia as a member of Capt. Peacock's Company, shortly afterwards volunteering for active service in the Land Transport Corps and was promoted to Sgt. He was present at the fall of Rangiriri and the advance to Ngaruawahia. He then transferred to the 2nd Waikato Regt. under Col. Hamilton and served during the balance of the Waikato war until the Battle of Orakau at which he was also present.

It was in July 1864 that Colonel Haultain, Commander of the 2nd Waikato Regiment brought his men to a place overlooking the Waipa River chosen by Lt. General Cameron of the British Army as a military base and with the idea of making it the capital of the region - this base became known as Alexandra, named in honour of Princess Alexandra of Denmark, wife of King Edward Vll. By the late 1860's, Alexandra had become a busy frontier town with two hotels, a bank, bakery, saddlers shop, forge, coach builder, pharmacy and several stores.