He was also a teacher of the Gianian Bunga (learning Institute), later becoming known as the "Amritsari Taksal", currently located in Sato Ki Gali.

His grandfather was Rao Ballu, a reputable warrior, who was a general in Guru Hargobind's army.

Mani Singh spent a considerable part of his life in service at Harmandir Sahib in Amritsar.

When Mani Singh was 13 years old, his father, Rao Mai Das, took him to Guru Har Rai at Kiratpur to pay homage.

[3][4] Mani Singh spent about two years at Kiratpur in the service of Guru Har Rai, scrubbing cooking pots and utensils.

Mani Singh remained in his company even after Gobind Rai ji had ascended the religious seat as Guru.

In 1687, when the Guru received a request for help from the widow of Baba Ram Rai, because the Masands were ill treating her, Guru Gobind Singh accompanied by Mani Singh went to Derah Doon, taught the Masands a good lesson and put them in their proper place.

Bhai Mani Singh was appointed Granthi of the Harmandir Sahib and Jathedar of the Akal Takhat.

Apart from Kirtan Singing of hymns from the Granth Sahib, Bhai Mani Singh used to do Katha (Exposition of Gurbani) which became a very popular daily feature.

Rahit Maryada was propagated and arrangements were made for administering Pahul (initiation) to new converts to the Khalsa fold.

When Guru Gobind Singh Ji left Anandpur on the night of 20 December 1704, his family got separated at river Sirsa in the confusion created by the Mughal attack.

[citation needed] After Banda Singh Bahadurs execution in 1716 The Khalsa abandoned their homes and escaped to the jungles of the Punjab, mountains of Sivalik Hills and deserts of Rajputana.

He expanded the first of Bhai Gurdas's Vaars into a life of Guru Nanak which is called Gyan Ratnavali[broken anchor].

[23] Mani Singh wrote another work, the Bhagat Ratnawali (sometimes called Sikhan di Baghat Mala), an expansion of Bhai Gurdas's eleventh Vaar, which contains a list of famous Sikhs up to the time of Guru Har Gobind.

[citation needed] In his capacity as a Granthi of Darbar Sahib at the Golden Temple, Bhai Mani Singh is also stated to have composed the Ardas (Supplication) in its current format; he also started the tradition of mentioning deeds of various Gursikhs with the supplication.

[24] After initiating the people of Majha to the Khalsa Panth Bhai Mani Singh came back to Anandpur Sahib.

He spent the period of worst persecution in post 1716 at the village of Baganwala (Nanaksar Bhaga) in Jhang district.

Around 1737, Bhai Mani Singh asked to Governor of Lahore, Zakaria Khan, for permission to hold the Diwali festival to celebrate Bandi Chhor Divas at the Harmandir Sahib.

The Governor alongside Diwan Lakhpat Rai[27] had different intentions and he sent secret orders to his forces to make a surprise attack on the Sikhs during the festival.

Bhai Mani Singh learned of this plan and sent messages to tell the Sikhs not to come; those that did left due to the presence of a military force and suspicious movement of the officers.