Baba Deep Singh is one of the most revered martyrs in Sikh history.
Throughout his life, he exemplified the saint-soldier spirit of the Khalsa.
He first joined Guru Gobind Singh and then Baba Banda Singh Bahadur to fight several wars against the Mughals.
When Ahmad Shah Abdali was returning to Kabul after enslaving hundreds of men and women from Hindustan, Baba Deep Singh rescued them in valiant attacks upon the Afghan army.
He ultimately sacrificed his life at the age of seventy-five when he mounted an attack to drive out the Afghans from Harmandir Sahib, the holiest Sikh shrine, thus restoring it to the Sikhs.
Baba Deep Singh was a scholar of Sikh theology and many languages, including Gurmukhi, Sanskrit, Persian and Arabic.
He assisted Bhai Mani Singh in writing the Pothi Sahib (now called Guru Granth Sahib) as dictated by Guru Gobind Singh at Damdama Sahib.
Baba Deep Singh also set up three taksals (academies) to propagate Gurbani and Sikh philosophy. These taksals still render invaluable service to this day.