The Singh Sabha Movement, also known as the Singh Sabha Lehar, was a Sikh movement that began in Punjab in the 1870s in reaction to the proselytising activities of Christians, Hindu reform movements (Brahmo Samajis, Arya Samaj) and Muslims (Aligarh movement and Ahmadiyah). The movement was founded in an era when the Sikh Empire had been dissolved and annexed by the British, the Khalsa had lost its prestige, and mainstream Sikhs were rapidly converting to other religions. The movement's aims were to "propagate the true Sikh religion and restore Sikhism to its pristine glory; to write and distribute historical and religious books of Sikhs; and to propagate Gurmukhi Punjabi through magazines and media." The movement sought to reform Sikhism and bring back into the Sikh fold the apostates who had converted to other religions; as well as to interest the influential British officials in furthering the Sikh community. At the time of its founding, the Singh Sabha policy was to avoid criticism of other religions and political matters.
Singh Sabha was successful in almost doubling the Sikh population by bringing new converts into Sikh fold. Sikhs were traditionally proselytising. Between 1901-1941, many Jats, OBC's, and Dalits converted to Sikhism due to outreach and preaching efforts of Singh Sabha movement.
Increased Mughal persecution of the Sikhs in the eighteenth century forced the Khalsa, which had raised arms against the state, to yield Gurdwara control to mahants, or custodians, who often belonged to Udasi, Nirmala, or other Brahmanical-influenced ascetic heterodox sects, or were non-Sikh altogether due to their lack of external identification, as opposed to initiated Sikhs. The Khalsa at this time engaged in guerilla campaigns against the Mughals and the hill-rajas of the Sivalik Hills allied to them; having vacated the Punjab plains, they launched attacks from the refuges of the northern hilly areas adjoining Punjab, and the desert areas to the south.