In February-March 1818, Bhopal became a princely state in British India as a result of the Anglo-Bhopal treaty between the East India Company and Nawab Nazar Muhammad (Nawab of Bhopal during 1816-1819). Bhopal state included the present-day Bhopal, Raisen, and Sehore districts, and was part of the Central India Agency. It straddled the Vindhya Range, with the northern portion lying on the Malwa plateau, and the southern portion lying in the valley of the Narmada River, which formed the state's southern boundary. Bhopal Agency was formed as an administrative section of Central India, consisting the Bhopal state and some princely states to the northeast, including Khilchipur, Narsingarh, Rajgarh, and after 1931 the Dewas states. It was administered by an agent to the British Governor-General of India.