NĀNAK PRAKĀSH, by Bhāī Mahendranāth Bose, is a biography of Gurū Nānak in the Bengalī language. The author was a follower of Keshabchandra Sen, and the followers of Sen used the word Bhāī or Rev. Bhāī for one another to convey a sense of close kinship and brotherhood. He had lived in the Punjab in 1871 in connection with his missionary work, and had learnt Punjabi and acquainted himself with Sikh literature. He planned to write a life-sketch of Gurū Nānak and began serializing his account in the Bengalī journal Dharmatatva (July 1883). Interrupting the series, he started work on a book Nānak Prakāsh, the first part of which was published in 1885 and the second in 1893.
The Nānak Prakāsh is based mainly on Bālā Janam Sākhī, though the author was not unfamiliar with other versions of the Sākhī literature. He had access to sources available in English as well. Of Trumpp's work on the Gurū Granth Sāhib, published in 1877, he was sharply critical. The first part of Bose's book covers the Gurū's life up to the eve of his preliminary. Udāsīs or preaching tours; the second embraces all of his four major Udāsīs and his life at Kartārpur. According to the author, Gurū Nānak preached what constituted the essence of Hinduism and Islam. Harmony was the keynote of his message. The book concludes with a brief account of the development of the Sikh community till 1708, the year Gurū Gobind Siṅgh, the last in the line of the ten spiritual teachers of the Sikhs, passed away. This portion is very sketchy and suffers from several chronological inaccuracies.