John Rodolphus Kent, known to his Maori friends as Amukete, is of obscure origin, neither his parents' names nor his date and place of birth being known. An officer in the Royal Navy, serving the government of New South Wales, he first entered New Zealand history as captain of the schooner Prince Regent, which left Port Jackson (Sydney) on 15 February 1820 as tender to the naval storeships Dromedary and Coromandel. During their survey of northern timber resources Kent was able to explore the Hokianga and other Northland harbours. His work was interrupted by the arrest of the American sealing ship General Gates for smuggling convicts out of Port Jackson; Kent took the documents of arrest to Port Jackson, then returned to survey parts of the coast as far as the Firth of Thames. Kent's was the first European vessel to traverse Rangitoto channel and enter Waitemata Harbour. Kent's survey plan of part of the harbour, sketched on 21 August 1820, was subsequently published in London by John William Norie. Kent returned to Port Jackson on 18 October 1820 with a cargo of spars.
In 1821 Kent undertook a long voyage to Hawaii as captain of the cutter Mermaid, accompanying the Prince Regent, which had been given as a gift by George IV to Kamehameha II of Hawaii. Kent returned to Port Jackson on 24 January 1823.
On 7 May 1823 Kent took the Mermaid to Foveaux Strait to investigate the possibility of establishing a flax trade. His log from 8 May to 15 August 1823 gives an admirable description of the district and shows the care Kent took to avoid giving offence to the Maori, whose customs and beliefs he described. Working in freezing, waist-high water, Kent and his men filled 14 large casks with flax; they also bought 1,100 pounds of dressed flax, and rooted 25 flax plants for transportation in tubs. Kent subsequently visited several South Island harbours, sketching coastal profiles as an aid to navigation, and naming Otago Harbour Port Oxley in honour of the surveyor general of the colony. He returned to Port Jackson on 15 August. On 5 November 1823 Kent took the Elizabeth Henrietta, a Sydney-built brig of about 150 tons, on a return visit to Foveaux Strait for a cargo of flax. The brig was driven ashore on Ruapuke Island on 25 February 1824. She was eventually refloated and returned to Port Jackson on 13 March 1825.
Kent left government service in 1826 and was given command of the Hawkesbury brig Elizabeth, owned by Daniel Cooper and Solomon Levey, for a sealing voyage to southern New Zealand and the Seal Isles. He sailed from Port Jackson on 14 March 1826 and left his gangs (including the diarist John Boultbee) in Fiordland while he continued his search for seals. It soon became evident to him that the improvident slaughter of seals had brought the trade to an end and he sailed north to set up a trading post in Hokianga in mid 1826. On a later voyage the Elizabeth sailed from Port Jackson on 6 April 1827 with two captains aboard, so that Kent could disembark at his Hokianga station and Captain William Wiseman could continue the voyage.
From 1827 Kent lived at Koutu Point in Hokianga under the patronage and protection of the Ngati Korokoro tribal leader Moetara, and formed a liaison with his daughter Wharo. In 1828 he moved to Kawhia to trade with the Waikato Maori. There he met Te Wherowhero, paramount chief of the Waikato tribes and later the first Maori King, and married Tiria, his daughter.
From 1827 to 1837 Kent conducted a thriving trade with his Maori hosts. He took cargoes of spars, flax, pork and potatoes across the Tasman Sea and loaded merchandise in Port Jackson for New Zealand. A typical cargo (recorded for the Lord Liverpool ) consisted of merchandise, muskets, gunpowder and liquor. Although his home was in New Zealand, Kent crossed and recrossed the Tasman in various vessels, the Elizabeth, the Industry, the Emma Kemp, the Governor Macquarie, the Lord Liverpool and the Lord Byron. He travelled as captain, as supercargo, as agent for Francis Mitchell or as a passenger. In 1833 he was appointed 'Trading Master and Interpreter' for the naval ship Buffalo. After the plunder of the Lord Byron by Maori in 1834, and Kent's subsequent retirement to Kaitotehe, near Taupiri, his flax trading activity became based at Ngaruawahia, centre of the trade routes for the Waikato River and the Manukau Harbour.
But ill health took its toll and on 8 September 1836, when the catechist James Hamlin visited Kent in his Ngaruawahia home, he found him ill with gout. John Rodolphus Kent died at Kahawai on the Manukau Harbour on 1 January 1837 and on 3 January he was buried by his Maori friends in a cemetery on the Te Toro promontory. A collection of Kent's northern profiles is preserved in the Hydrographic Department at Taunton, Somerset, England.