The painter of this miniature portrait is not known for sure. However, if the sitter is aged 36 or less in the miniature, and with the help of a kind visitor as noted further below, it is most likely painted by his father, William Stevenson. Thus for the purpose of this description, he is considered to be aged 36!
It it is inscribed on the reverse "celebrated numismatologist. Stevenson, Norwich. Father of Adelaide who married John Deighton of Cambridge." Thus the sitter is identified as Seth William Stevenson (1785 – 1853) who wrote a 929 page book entitled "Dictionary of Roman Coins". This was published in 1889 after his death and remained in print for about another 100 years.
In the 1851 census, Seth William Stevenson was a widower, his wife being Mary (1801- <1851). He was then aged 63 and is recorded as the co-proprietor and editor of the Norfolk Chronicle weekly journal. In 1851 he lived at 173 Surrey Street Norwich, along with his daughter Adelaide, then aged 21 and his son Henry aged 18 who later assisted completion of the book after his father's death. 1061.
A kind visitor has provided the following extra information;
"Did you know that Seth William Stevenson’s father was a miniature painter ? Apparently he trained at the Royal Academy and was a pupil of Rubens. William Stevenson lived from 1749 to 1821 He was also a publisher and author and Sheriff of Norwich in 1799. He was Co-proprietor of the Norfolk Chronicle. There is a substantial monumental inscription to William and his wife in St Stephen’s church in Norwich.
His son Seth William Stevenson (1785 – 1853) succeeded his father as proprietor and virtual editor of the Chronicle. He also served in the office of Sheriff of Norwich in 1828, and as Mayor in 1832.
Upon Seth’s death his son Henry Stevenson (1832/3) succeeded him as Proprietor of the Chronicle and served as Sheriff of Norwich in 1875. He retired before his death in 1888 and died a chronic alcoholic. Henry Stevenson was widowed from his first wife and then married my great aunt, Ann Emilia Self.
In family documents there are references to the Stevenson family silver, much of which is owned by descendants within my family in New Zealand. By all accounts they were wealthy. My great grandmother also writes of ‘exquisite miniatures, & family portraits’ in the Stevenson estate."