He served as engineer aboard HMS Erebus during the 1845 Franklin Expedition, which sought to explore uncharted parts of what is now Nunavut, including the Northwest Passage, and make scientific observations.
He was baptized in the Church of St. Michaels, Angel Meadow, a chapel of ease in the most notorious slum of the city during the nineteenth century.
[5] In addition to the engines, Maudslay, Sons & Field provided two men to maintain them: James Thompson on Terror and John Gregory on Erebus.
[6] Warrant officers served as heads of specialist technical branches aboard ship and reported directly to the captain.
On 9 July 1845, two weeks after Erebus and Terror departed Greenhithe, Kent, he wrote a letter to his wife in which he described his first time seeing whales and icebergs.
The letter concluded with the line “Give my kind Love to Edward, Fanny, James, William, and kiss baby for me – and accept the same yourself.
[11] In April 1848, the ships were still beset by the ice, in the northern Victoria Strait and twenty-one men including John Franklin had died.
[12] John Gregory survived three years trapped aboard Erebus and was one of the survivors led by Crozier south along King William Island.
[14][15] He found in Erebus Bay a ship's boat resting on its sledges, large quantities of supplies and personal effects, and the partial remains of two skeletons.
[12] An expedition consisting of Frederick Schwatka, William Henry Gilder, Heinrich Klutschak, Frank E. Melms, and Ipirvik ("Joe Ebierbing") explored the same area in 1879.
[12] Gregory's skull was rediscovered by amateur historian Barry Ranford in 1993, who had initially believed it to be a bleached plastic bottle while sledging along King William Island.
[18] Using the skull as a base, a facial reconstruction of John Gregory was made by Diana Tretkov prior to the identification of the remains.