By rejecting the figures of Nabonidus we cut away our only external connection with the chronology of the later periods, and, in order to evolve a scheme for earlier times we have to fall back on a process of reckoning from below. Without discussing in detail the later chronology, it will be well to indicate briefly the foundations on which we can begin to build. By the aid of the Ptolemaic Canon, whose accuracy is confirmed by the larger List of Kings and the principal Babylonian Chronicle, the later chronology of Babylon is definitely fixed back to the year 747 B.C.; by means of the eponym lists that for Assyria is fixed back to the year 911 B.C. Each scheme controls and confirms the other, and the solar eclipse of June 15th, 763 B.C., which is recorded in the eponymy of Pûr-Sagale, places the dead reckoning for these later periods upon an absolutely certain basis. For the earlier periods of Babylonian history, as far back as the foundation of the Babylonian monarchy, a chronological framework has been supplied by the principal List of Kings.[9] In spite of gaps in the text which render the lengths of Dynasties IV. and VIII. uncertain, it is possible, mainly by the help of synchronisms between Assyrian and Babylonian kings, to fix approximately the date of Dynasty III. Some difference of opinion exists with regard to this date, but the beginning of the dynasty may be placed at about the middle of the eighteenth century B.C. With regard to Dynasty II. of the King's List it is now known that it ruled in the Sea-country in the region of the Persian Gulf, its earlier kings being contemporary with the close of Dynasty I. and its later ones with the early part of Dynasty III.[10] Here we come to the first of two points on which there is a considerable difference of opinion. The available evidence suggests that the kings of the Sea-country never ruled in Babylon, and that the Third, or Kassite, Dynasty followed the First Dynasty of Babylon without any considerable break.[11] But the date 2232 B.C., which probably represents the beginning of the non-mythical dynasties of Berossus,[12] has hitherto played a considerable part in modern schemes of chronology, and, in spite of the fact that no amount of ingenuity can reconcile his dynasties with those of history, there is still a strong temptation to retain the date for the beginning of Dynasty I. of the Kings' List as affording a fixed and certain point from which to start calculations. But this can only be done by assuming that some of the kings of the Sea-country ruled over the whole of Babylonia, an assumption that is negatived by such historical and archaeological evidence as we possess.[13] It is safer to treat the date 2232 B.C. as without significance, and to follow the evidence in confining the kings of the Sea-country to their own land. If we do this we obtain a date for the foundation of the Babylonian monarchy about the middle of the twenty-first century B.C.