The declaratory judgment by that name is comparatively new in legal procedure in this country. But it is in reality simply an extension of an old process. The power to declare the rights of the parties is inherent in courts of equity and has been exercised since ancient times in action to quiet title, to declare marriages valid or void, to annul divorces, to declare legitimacy or illegitimacy or determine heirship, to construe wills and trusts, and in other actions. A suit for a declaratory judgment in no wise differs from other suits save in the single respect of the relief asked. The parties must be adverse, they must have an immediate and material interest in the adjudication, and there must be a real controversy as to which the judgment shall be final. The fact that the relief asked is a mere declaration of rights does not deprive the action of its justiciable quality. Process by way of enforcement is not necessary to give finality to a judgment. These principles are now well recognized in the state courts. Declaratory judgment legislation has been adopted in twenty-nine States and upheld, except in a single case (now overruled), wherever the question has arisen.