The best treatment of the MB II–LB I transition is Aharon Kempinski, Syrien und Palästina. On the basis of a set of astronomical observations, we know that the ninth year of Pharaoh Amenophis I was 1536 B.C. We also know that Pharaoh Thutmosis III was on the throne in 1469 B.C. (Depending on where the astronomical sightings were made, these dates could be lowered by 20 years, to 1516 B.C. and 1449 B.C., but the difference is not really material, and the likelihood is that the early chronology is correct.)
From these dates, other dates are firmly fixed by contemporary regnal references. Working from these dates on the basis of these records, we know that Pharaohs Amenophis III and Amenophis IV (Akhenaten) ruled from about 1405 to 1350 B.C.
We can correlate the rule of Amenophis III and Amenophis IV with the Amarna texts, several hundred cuneiform tablets discovered at the Egyptian capital of Amenophis IV at Tell el-Amarna. These letters were sent and received during the reign of Amenophis III and Amenophis IV. They are letters primarily to the Egyptian court from Egyptian vassals in Canaan, and from contemporaries such as Assur-uballit of Assyria, whose reign can be dated independently (by Assyrian king lists) to about 1365–1330 B.C.
The Amarna letters, from the period of roughly 1375–1345 B.C., provide a window on contemporary Canaan, in which certain towns are major centers of great territorial and administrative importance. These towns are the great citadels of the Late Bronze II A period. If we superimpose the LB II A archaeological picture (as at Gezer, Shechem and Megiddo) on the Tell el-Amarna correspondence, the lines match precisely. Further, two letters, one with characters known from the archive, have been found in LB II A levels at Canaanite sites. (One is a letter from Kamid-el-Loz, in D. O. Edzard et al., Kamid el-Loz—Kumidi [Bonn: Habelt, 1970], pp. 55f. Another, EA 333, in J. A. Knudtzon, Die El-Amarna Tafeln [Vorderasiatische Bibliothek 2; Leipzig, Germany: Hinriches, 1915], p. 333, was uncovered at Tell Hesi.) Consequently, LB II A, during which Canaan developed to the stage reflected in the Amarna archive, begins no later than 1400; at some sites, of course, it may have begun earlier.