 This work has been highly influential in the field of Rumi studies worldwide.Nicholson translated the famous Persian book on sufism Kashf ul Mahjoob in English written by famous saint of Subcontinent 
Ali Hujwiri Daata Ganj Bakhsh 

Being a teacher of the then Indian scholar and poet Muhammad Iqbal, Nicholson translated Iqbal's first philosophical Persian poetry book Asrar-i-Khudi into English as "The Secrets of the Self".Among Nicholson's students was A. J. Arberry, a translator of Rumi and the Quran.