He was illiterate and his name is known to have been spelt in 5 different ways apart from Trevan, 3 of which are distinctly separate families, which makes researching him extremely difficult.
He died in Creswick, Victoria, Australia on 31 Jul 1867. His certificate records that he lived in Victoria for 13 years. It appears that they lived in Southern Australia before moving to Victoria.
Following his death his widow lived with son JH Carew Trevan. She died on 20 Dec 1880 in Horsham and she was taken by train to Creswick where she was buried with John 2 days later. Her death certificate shows 11 years in Southern Australia and 21 years in Victoria.
According to a descendent, Lyn Breuer, he married Annie and they had at least 7 children, including her great grandmother Sarah Ann Trevan who married John Henry Head.
Another descendent, Ro Spencer, has an extensive tree of their descendents. She has him marrying Nanny (Annie) Wasley on 27 Mar 1856 and having 14 children.
The following is from the The Creswick & Clunes Advertiser or County of Talbot Agricultural Journal:
Trevan William Henry Funeral 2-Jul-1861 Funeral of William Henry Trevan.
On Thursday evening last, Richard Trevan of this town, received
intelligence, per express, that his brother William Henry Trevan had
been killed by the falling of a heavy mass of rock, in a claim of
Simmond's Reef Company, at Blackwood. He at once - although at a
distance of 42 miles - made arrangements to have the mortal remains of
his relative brought over to Creswick. Mr Dennis, proprietor of one of
the Ballarat coaches, undertook the task, but unfortunately, about seven miles before reaching Blackwood, one of the horses dropped down dead, and had to be replaced by another one. The party eventually reached Blackwood, on Friday, just after the inquest on the body of the deceased (and on the body of James Nankervis, killed at the same time) had been held. The mortal remains reached Creswick on Sunday at 1 p.m. and were committed to the grave the same day at 2.30 p.m. About 200 persons, several of whom were on horseback and in carriages, formed part of the funeral procession. In the absence of the Rev Mr King, Wesleyan Minister, who had to hold divine service at Kingston and Bullarook on that day, Mr T Cooper of Albert Street, was requested to conduct the religious ceremony. Mr Cooper read the funeral service in a very impressive manner, and after the singing of an appropriate hymn, the whole was concluded with prayer. Deceased, only 23 years of age, was very much respected.
This was copied from a site about the Dennis family.
| Date | Event | Surname | Parish |
| 26? / 20? Apr 1808 | Baptism | Trevean | Illogan |
| 1830 | Marriage | Trewin |   |
| 21 Mar 1833 | Baptism of child | Trevin of Brea | Illogan Church |
| 12 Dec 1834 | Baptism of child | Treven of Brea | Illogan Church |
| 21 Sep 1839 | Baptism of child | Trevan of Brea | Camborne Church |
| 6 Jun 1841 | Census | Trevena | Brea, Illogan |
| 23 Dec 1841 | Burial of child | Trevan of Brea | Illogan Church |
| 1848 | Emigration to Australia, Southern Australia | Trevan | Ship called Rajah |
| 1854/5 | Migration to Victoria | Trevan | Inferred from information on death certificates, which for Victoria indicate how long individuals have lived in the state. |
| 31 Jul 1867 | death of John Trevan | Creswick, Victoria, Australia | |
| 22 Dec 1880 | death of Sarah Trevan | Horsham, Victoria, Australia | |
| 24 Dec 1880 | burial of Sarah Trevan | Creswick, Victoria, Australia |
Notes:
| Surname | First Name | Type | Place | Date | Page |
| Trevan | John | Land Sale | Creswick | 01 Feb 61 | 4 |
| Trevan | John | News | Creswick | 02 Apr 61 | 2 |
| Trevan | Richard | News | Creswick | 02 Jul 61 | 2 |
| Trevan | William Henry | Funeral | Blackwood | 02 Jul 61 | 2 |
| Trevan | William Henry | Death | Mt Blackwood | 02 Jul 61 | 2 |
| Treven | J | Court | Creswick | 30 Apr 61 | 2 |
| Trevan | J | Court | Creswick | 03 May 61 | 2 |