Haydon was a enthusiastic architect, sketcher, explorer, naturalist and writer who lived in the Port Phillip area from 1840 to 1845. He demonstrated a sympathic interest in the local Aborigines and was involved in the exploration of the local area. In 1844 he took part in an expedition with George Augustus Robinson from Melbourne to Alberton (for details see G. Mackaness, ed. George Augustus Robinson's Journey into South-Eastern Australia, 1844).
After his return to England in 1845 Haydon published his Five Years' Experience in Australia Felix (1846) which 'brought him recognition as an authority on Australian life' (OCAL). His novel The Australian Emigrant (1854), with illustrations taken from his sketches, is also based on his experiences in Australia.