The kudurru or boundary-stone had its origin under the Kassite kings, and, while at first recording, or confirming, a royal grant of land to an important official or servant of the king, its aim was undoubtedly to place the newly acquired rights of the owner under the protection of the gods. A series of curses, regularly appended to the legal record, was directed against any interference with the owner's rights, which were also placed under the protection of a number of deities whose symbols were engraved upon the blank spaces of the stone. It has been suggested that the idea of placing property under divine protection was not entirely an innovation of the Kassites. It is true that the foundation-cones of the early Sumerian patesi Entemena may well have ended with elaborate curses intended to preserve a frontier-ditch from violation.[65] But the cones themselves, and the stele from which they were copied, were intended to protect a national frontier, not the boundaries of private property. Gate-sockets, too, have been treated as closely related to boundary-stones, on the ground that the threshold of a temple might be regarded as its boundary.[66] But the main object of the gate-socket was to support the temple-gate, and its prominent position and the durable nature of its material no doubt suggested its employment as a suitable place for a commemorative inscription. The peculiarity of the boundary-stone is that, by both curse and sculptured emblem, it invokes divine protection upon private property and the rights of private individuals. In the age of Hammurabi we have no evidence of such a practice, and the Obelisk of Manishtusu,[67] the far earlier Semitic king of Akkad, which records his extensive purchases of land in Northern Babylonia, is without the protection of imprecatory clauses or symbols of the gods. The suggestion is thus extremely probable that the custom of protecting private property in this way arose at a time when the authority of the law was not sufficiently powerful to guarantee respect for the property of private individuals.[68] This would specially apply to grants of land to favoured officials settled among a hostile population, especially if no adequate payment for the property had been made by the Kassite king. The disorder and confusion which followed the fall of the First Dynasty must have been renewed during the Kassite conquest of the country, and the absence of any feeling of public security would account for the general adoption of such a practice as placing land in private possession under the protection of the gods.