The use of stone stelæ for this purpose may well have been suggested by a Kassite custom; for in the mountains of Western Persia, the recent home of the Kassite tribes before their conquest of the river-plain, stones had probably been used to mark the limits of their fields, and these may well have borne short inscriptions giving the owner's name and title.[69] The employment of curses to secure divine protection was undoubtedly of Babylonian, and ultimately of Sumerian origin, but the idea of placing symbols of the gods upon the stone was probably Kassite.[70] Moreover, the kudurru was not the original title-deed recording the acquisition of the land to which it refers. As in the earlier Babylonian periods, clay tablets continued to be employed for this purpose, and they received the impression of the royal seal as evidence of the king's sanction and authority. The text of the tablet, generally with the list of witnesses, was later on recopied by the engraver upon the stone, and the curses and symbols were added.[71] A boundary-stone was sometimes employed to commemorate a confirmation of title, and, like many modern legal documents, it recited the previous history of the property during a long period extending over several reigns. But the majority of the stones recovered commemorate original grants of land made by the king to a relative, or to one of his adherents in return for some special service. Perhaps the finest of this class of charters is that in which Meli-Shipak makes a grant of certain property in Bît-Pir-Shadû-rabû, near the old city of Akkad or Agade and the Kassite town Dûr-Kurigalzu, to his son Merodach-baladan I., who afterwards succeeded him upon the throne.[72] After giving the size and situation of the estates, and the names of the high officials who had been entrusted with the duty of drawing up the survey, the text defines the privileges granted to Merodach-baladan along with the land. As some of these throw considerable light on the system of land tenure during the Kassite period, they may be briefly summarized. [KASSITE BOUNDARY STONES SET UP IN THE REIGNS OF MELI-SHIPAK AND NAZI-MARUTTASH. After Délég. en Perse, Mém. I, pl. XVI et XIV]