When Psametek I. opened the Egyptian ports to
foreign commerce (624 B. C.) it stimulated the Greeks to a new intellectual activity, but the reaction was disastrous to the old Egyptian civilization itself. It quickly invited foreign invasion, and first Cambyses subdued the country (525 B. C.) and later Alexander planted the city named after him, and under the splendid dynasty of the Ptolemies, Egypt became like a Grecian colony.
In its early times, the lower, middle and upper parts of Egypt usually had independent rulers, though all were essentially the same race of people. The separate and mixed records of these dynasties have thrown the early dates of Egyptian history into hopeless confusion. The most learned men of our day differ among themselves by 5,ooo years concerning dates which some of them place less than 5,ooo years back of our own time. Back of the sixteenth century,