Born on 22 August 1864, Barnet, Greater London (GRO), he studied art at the Slade School under Legros from 1883 on a three year scholarship,  and was exhibiting  Newlyn titles at the RBA at the end of that period (1885-86), demonstrating that he had spent time in Cornwall within his coursework.  At the Slade he not only won a Landscape prize, but also a medal for Painting from Life. He worked in Spain for a year (1886-87), and then returned to London to work with Herkomer at Bushey. From 1896 through 1897 he painted in Rome.

Haddon travelled far and wide, painting, and writing travel books including The Old Venetian Palaces and Southern Spain. In England he lived at Cambridge in his later years and died there on 13 December, 1941, age 77 (GRO).