Bhai Kanhaiya ji was founder of Sevapanthi or Addanshahi sect of the Sikhs. He was born in a Dhamman Khatri family of Sodhara near Wazirabad in Sialkot District (Now in Pakistan). His father was a wealthy trader, but he himself being of a religious bent of mind left home when still very young and roamed about With sadhus and ascetics in search of spiritual peace. His quest ended as he met Guru Tegh Bahadur 1621-75) and accepted initiation at his hands. Kanhaiya established a dharamsal at Kavha village in the present Attock district of Pakistan. Which he turned into a preaching centre. His special mission was selfless service of humanity with no distinction of nationality, caste or creed. In 1705, he was on a visit to Anandpur when Anandpur was invested by a combination of hill troops and the Mughal imperial army. During the frequent sallies and skirmishes, Bhai Kanhaiya used to roam around serving water to the wounded and the dying without distinction of friend and foe. Some Sikhs complained to Guru Gobind Singh that Kanhaiya had been resuscitating the fallen enemy soldiers. As Guru Gobind Singh summoned Bhat Kanhaiya and told him What the Sikhs had said, he spoke, "Yes, my Lord, what they said is true in a sense, but I saw no Mughals or Sikhs in the battlefield. I only saw the Guru's face in everyone. " The Guru, pleased with the reply, blessed him and told his Sikhs that Kanhaiya had understood his teaching correctly. Guru also give him medicine to be put on the wounds of fallen soldiers(Sikhs and Enemies).
After evacuation of Anandpur, Bhai Kanhaiya retired to Sodhara where he died in 1718. 

Excerpts taken from Encyclopedia of Sikhism
by Harbans Singh .
Published by Punjabi University, Patiala