With the Charter Act 1833 the Secretariat of the Government of the East India Company was reorganised into four departments, each headed by a secretary to the Government. The armies in the presidencies of Bengal, Bombay and Madras functioned as the respective presidency armies until April 1895, when the presidency armies were unified into a single Indian Army. For administrative convenience, it was divided into four commands: Punjab (including the North West Frontier), Bengal (including Burma), Madras and Bombay (including Sindh, Quetta and Aden).