Montagu- Chelmsford reforms introduced a system called?

Dyarchy or dual government is the division of powers in two authorities. This system was first introduced in India through the Montague-Chelmsford reforms in 1919.

In this form of government, the executive branch of each provincial government is divided into two sections. The various fields of administration will be divided between these two sections.

In British India government, Provincial governments included British members(Executive Councillors) and Indian members (ministers from Legislative council). In order to provide administrative authorities to Indian members, the dyarchy was introduced and the concept of transferred and reserved subjects was introduced.

The reserved subjects include matters of high importance like law and order, revenue and justice and transferred subjects include matters of local administration like education, public health etc. In this way, Indians got some powers to administer themselves yet the crucial subjects were dealt by British executive Councillors.