Guru Har Krishan, born 17 July 1656 – 9 April 1664 was the eighth of the ten Sikh Gurus. At the age of 5, he became the youngest Guru in Sikhism on 7 October 1661, succeeding his father, Guru Har Rai Ji. He contracted smallpox in 1664 and died before reaching his 8th birthday.
He is also known as Bal Guru (Child Guru), and sometimes spelled in Sikh literature as Hari Krishan Sahib. He is remembered in the Sikh tradition for saying "Baba Bakale" before he died, which Sikhs interpreted to identify his granduncle Guru Tegh Bahadur Ji as the next successor. Guru Har Krishan Sahib Ji had the shortest reign as Guru, lasting only 2 years, 5 months and 24 days.
Guru Har Krishan was born in Kiratpur (Shivalik Hills) in northwest Indian subcontinent to Krishen Devi (Mata Sulakhni) and Guru Har Rai. His father, Guru Har Rai supported the moderate Sufi influenced Dara Shikoh instead of conservative Sunni influenced Aurangzeb as the two brothers entered into a war of succession to the Mughal Empire throne.