A dera is an establishment around a living head, with a seat, a following and property. Punjab has several hundred, of very different kinds: Sikh deras of the Nirmala, Udasi and Sevapanthi orders; the Namdhari and Nirankari deras; Radha Soami at Beas; Dera Sachkhand Ballan of the Ravidassia community; and Dera Sacha Sauda at Sirsa.
Their followings are drawn disproportionately from Dalit and landless communities, which is the fact that explains most of what they are. A village gurdwara controlled by dominant-caste households is not a neutral space, and a dera with a living head who accepts everyone is an alternative.
Radha Soami Satsang Beas, founded 1891, has a following in the millions across many countries, runs a large hospital and does not take donations at the satsang.
Deras have become electorally significant, because a head's endorsement can move votes in a district, and this has been openly courted by every party.
The clashes between Sikh organisations and particular deras, over doctrine, over imitation of Sikh forms, and over the events of 2007 and 2015, have produced deaths and prolonged unrest. This is one of the most consequential and least honestly discussed subjects in Punjab.
Punjab has thousands of deras and the largest of them have followings in the millions, their own scripture or practice, their own property and their own succession disputes.
Their following is disproportionately from the landless and the Scheduled Caste communities, which is the fact that explains their political weight and the hostility toward them.
The confrontations between deras and Sikh institutions are read as theological and are also about caste, land and votes, and any account that leaves those out is not describing what is happening.