The realm of England was claimed by the Conqueror and his successors on the throne. On the theory of possession by conquest, the feudal system of tenure was built and developed. The Sovereign granted land to his soldiers and favourites, or left it in possession of the ancient holders, at his own pleasure. In return, those who enjoyed the property undertook various obligations to the lord paramount, such as military services. The grants were at first made for the lifetime of the holders; but ere long the rights and duties were extended to the succeeding heirs. Landowners holding thus of the king conveyed portions of their estates to their retainers, in return for services to be rendered. These services were usually either of a military or an agricultural character. With the advance of time, the progress of civilization, and the development of the arts of peace, the latter mode of compensation for the use of land gradually superseded the former; and after the Restoration the feudal burdens were abrogated by law. Since the abolition of these uncertain incidents of land tenure, the obligations subsisting among the holders of the several rights and interests pertaining to lands and tenements have been reducible to a money standard, with at least an approximation to justice and accuracy.