Brajabuli is an artificial literary language popularized by the Maithili poet Vidyapati.
[1][2] Among the medieval Bengali poets who wrote in Brajabuli are Narottama Dasa, Balarama Das, Jnanadas, and Gobindadas Kabiraj.
[4] Rabindranath Tagore also composed his Bhanusimha Thakurer Padavali (1884) in this language (he initially promoted these lyrics as those of a newly discovered poet, Bhanusingha).
[3] Other 19th century figures in the Bengal Renaissance, such as Bankim Chandra Chattopadhyay, have also written in Brajabuli.
[5] Brajabuli is basically Maithili (as prevalent during the medieval period), but its forms are modified to look like Bengali.