Girish Chandra Sen was the first Bengali to translate Qur'an in Bengali language during 1886. He was not an upstart but a scholar who read extensively about Islam for some years before embarking on the translation of Qur'an in Bengali. He was a Brahmo missionary and did so at the behest of Brahmo leader Keshub Chunder Sen (Keshab Chandra Sen). The latter also asked other three Brahmo scholars to study and understand Hinduism, Buddhism and Christianity respectively. The very idea was to find converging aspects of all major religions of India.
At that time, Muslim religious scholars of Bengal could not even imagine such thing. To them Bengali language was of no standing before Arabic. But, now when we see that many Bengali Muslim scholars have translated Qur'an in Bengali, we understand that Bengali language has come a long way. This however, cannot take away the credit from Girish Chandra Sen.
Possibly some Bangladeshi Islamic scholars are not happy with Girish Chandra Sen. While talking to the Principal of a renowned Madrassa of Bangladesh a couple of years back on the topic; I could smell his annoyance with Girish Chandra Sen. The Principal even said "tore beta ke bolechhilo Kuran onubad korte?" To him, in all probability, it was unbecoming of a Hindu (Brahmo) to do such thing. I think, on the contrary, the said Principal was to feel happy. But he did not. Old habits die hard.