Sri Guru Hari Krishan Sahib, became the eighth Guru of the Sikhs on October 6, 1661 A.D. During the short period of his pontificate He guided the Sikh community with great tact and wisdom in the face of threatening challenges. He sent missionaries to the farthest outposts of the country and inspired the seekers who came to Him with eternal truth and the highest mystical and spiritual experiences. His father Guru Hari Rai Ji had disowned his elder brother, Ram Rai because he went out of the way to please the Mughal Emperor, more so by showing magical miracles to entertain him.
When Guru Har Krishan Sahib came to Delhi , he was entertained as a royal guest by Raja Jai Singh in his Haveli (Palace), the present site of Gurdwara Bangla Sahib. This palace was built on the model of existing palace of Raja Jai SINGH in Jaipur. Raja Jai Singh’s Chief Rani looked after Mata Sulakhani, the mother of the Guru Sahib, and was greatly impressed by the spiritual powers of the child-prophet.
Avoiding invitations and meetings with Emperor Aurangzeb he refused to show any occult miracles of the type Ram Rai had shown in the Mughal Court and had got many rewards. During this period Small pox and cholera had broken in Delhi and Guru Harkrishan Sahib moved among the poorest Hindu and Muslim localities helping the suffering and the sick. Hindus and Muslims of Delhi were deeply moved by his compassion and human concern for all those who suffered from poverty and diseases. Every day Guru Harkrishan Sahib distributed sanctified water to the sick and ailing people which had a miraculous healing effect on their mind, body and soul. To this day water sanctified by the Word of God, sung all day in this Gurudwara sahib , is distributed to those seeking faith healing. Many seriously ill persons are reported to have been healed. Raja Jai Singh dedicated his palace to his sacred memory and since his death it has been the place of worship of the Sikhs and is known as Gurudwara Bangla Sahib.