The term sovereignty means supremacy or the right to demand obedience. A sovereign state is one which is subordinate to no other. It is supreme over the territory under its control. It issues order which all humans and associations within its territory are bound to obey. Its independence in the face of other communities is the mark of external sovereignty. Its power to exact obedience from its member is the mark of internal sovereignty, so that sovereignty is the chief of attribute of statehood.
In ancient times, there was o concept of sovereignty as it is understood in modern times. The concept of state sovereignty came into being after the Middle Ages and developed during the reformation and renaissance. Bodin was the first writer who used the word sovereign by which he meant the absolute and perpetual power within state. According to him, the ruler is the sources of all laws. It has the absolute power of law making although the law of nature makes him respect proprietary rights and keep faith with another ruler.
The theory of sovereignty was further developed by Hobbes. According to him, sovereignty is absolute and not bound by anything. Its power extends over all matters within state, including religion. The theory of sovereignty was given in a very elaborate and systematic form by Austin. Austin said that sovereignty is not in the habit of obedience to any political superior and he commands habitual obedience from the bulk of his subjects. He further said that sovereignty is indivisible, unlimited and illimitable.
Salmond regarded that every political society involves the presence of sovereign authority. It is not necessary that sovereignty in all cases be found in its entirety within the confines of the state itself and may, wholly or partly, be external to the state. Sovereignty need not mean unlimited supremacy as supposed by Austin. He said that an authority may be sovereign within its sphere and in that sphere its power is uncontrolled.
Dicey saw that there are two kinds of sovereign, they are legal sovereign and political sovereign. Parliament is the legal sovereign because it has the supreme power of law-making. Behind the legal sovereign, there is the political sovereign which is the electorate. The legal sovereign acts in accordance with the wishes of the political sovereign.
The view of Kelsen is that there can be no concept of sovereignty distinct and separate from and above the law. The state is simply a legal order. The only meaning that can be given to state sovereign is that legal order is a unity distinct from and independent of other similar.
Duguit rejected idea of state sovereignty. According to him social solidarity is the end of all human institutions, including the state. The state has no absolute and unlimited powers. It is bound by the rule of social solidarity. State sovereignty is a meaningless term as the state has no supreme and superior powers.