Dadu Dayal was a saint from Rajasthan in northern India. "Dadu" means brother, and "Dayal" means "the compassionate one". He lived in the second half of the sixteenth century (1544-1603). His songs are in a Hindi dialect known as Braj Bhasa, being a mixture of Hindi and Rajasthani.
Like the earlier saint Kabir, Dadu came from one of the many low artisan castes that had converted to Islam. He lived in the Jaipur region of Rajasthan, most probably as a pinjari, a cotton carder. He married and had a family of two sons and two daughters.
He gathered around himself a group of followers, which became known as the Dadu-panth. This organization has continued in Rajasthan to the present-day, and has been a major source of early manuscripts containing songs by the North Indian saints.
Dad himself did not write down any of his compositions. These were recorded by his disciple Rajjab. Another disciple, Janagopal, wrote the earliest biography.
Dadu clearly experienced the bliss of Sahaja, and alludes to it in his songs, some of which are presented in translation in the linked pages.
Surviving songs do not record the name of Dadu's guru, but it is possible that he was given realisation by one of Kabir's sons. Certainly much of the imagery used in his songs is similar to that used by Kabir, and similar also to that used by the earlier Sahajiya Buddhists and Nath yogis.
Source : John Noyce, Melbourne, Australia