12 The Calendars and Chronology Dynasty VII......... 2294-2248 Dynasty VIII (an overlapping dynasty) ends .... 2239 Interregnum......... 2239-2233 Dynasties IX, X, XI (overlapping)..... 2233-1990 Dynasty XII......... 1990-1777 Dynasty XVIII ......... 1573-1314 Dynasty XIX......... 1314-1194 Controversy has revolved mainly on the durations of the two periods when United Egypt broke up into petty kingdoms; the first from the end of the Sixth Dynasty to the time when the Theban princes of the Eleventh Dynasty (Mentuhotep I-V) assumed the rule of the Two Lands. Putting this date at about 95 years before the beginning of the Twelfth Dynasty, the ^first intermediate period' then lasted about 209 years, which agrees well with the cultural evidence. The second intermediate period lasted from 1777 to 1573. This also agrees with the inferences drawn from the cultural evidence. An assured chronology of Egypt is important for the syn- chronisms established with periods in the history of other races. Thus the epoch of Menes was contemporary with the Jemdt Nasr period of Sumer, and also with the first cultural period (Early Minoan I) of Crete. The date of Menes thus provides an important key date in the history of Mesopotamia and in that of Knossos. The destruction of Knossos is similarly deter- mined by the cultural synchronisms as having occurred about 1400. The closing years of the Nineteenth Dynasty again determine the date of the Siege of Troy as occurring between • 1200 and 1195. Finally, new light is thrown on the chronology of the second intermediate period, and of the Eighteenth Dynasty by Mr. Sidney Smith's work, Alalakh and Chronology* He proves that the First Dynasty of Babylon must be dated as lasting from 1 At the moment of writing, Mr. Sidney Smith's work is in the press. I am much indebted to Mm for kind permission to make use of his con- clusions.