Who first propounded the theory of the Doctrine of Separation of Powers?

Explanation: The theory of Doctrine of Separation of Power was first propounded by Montesquieu, a French scholar in and 1747 published in his book ‘Espirit des Louis’ (The spirit of the laws). Montesquieu found that if the power is concentrated in a single person’s hand or a group of people then it results in a tyrannical form of government. To avoid this situation with a view to checking the arbitrariness of the government he suggested that there should be clear-cut division of power between the three organs of the state i.e. Executive, Legislative and the Judiciary.