The name of Bongaigaon town and district is the elongation of a fig and old village named Bongaigaon alias Bong-ai-gaon situated on the southern border of the town. According to hearsay in the long past there were plenty of wild(Bon) Cows (Gai) in the surrounding hilly and forest areas. So, the villagers assembled time to time to drive away the wild cows for protecting their crops. Thus this area was popularly known as Bon-Gai-Gaon. In that big village areas there dwelt one nature-poet named 'Bong' (Bong Roy) who could induce laughters to all his bye-standers with his cryptic but harmless oral composition describing the situation on the spot and in return he could collect grains or coins voluntarily offered by the audiance. This was his only source of income and profession. Thus his areas was roughly identified as the village of Bong(Ray) i.e. Bong-er-Gaon=Bongaigaon that is in course of time. This Bongaigaon village area was famous for orange fruits which were sold inter-alia other agricultural products in the nearest market named Birjhora Bazar located at the heart of present Bongaigaon town.The word Birjhora was derived from Bir+Jirowa(Jirowa means resting place) of Bir(hero). It is held that the noble hero Chilarai took here rest for about two months during rainy season at the time of his invading the neighbouring Kingdoms of entire north-east India.