We have already seen the evidence for the migration of Minoan tribes of a later age in the assault of the Zakkaru and Pulosathu upon Egypt 200 years after the fall of Knossos, and the establishment of the latter tribe as an independent power upon the coast of Palestine--events which may have been due to the advance of another wave of Northern colonists upon the shores of Crete. One more glimpse of the dying sea-power of the Cretan race, now itself disorganized and predatory, is given us by the Golenischeff papyrus, which tells, among other adventures of the unfortunate Wen-Amon, envoy of Her-hor, the priest-King of Upper Egypt (_circa_ 1100 B.C.), how the Egyptian ambassador was threatened with capture by eleven ships of Zakru pirates, who put into Byblos when he was about to sail thence. Whether these were genuine Minoans or not, it is impossible to tell; their immediate connection was apparently with Dor, on the coast of Palestine; but their name suggests the town of Zakro, in Eastern Crete, and it is not unlikely that they belonged to the same race as the Zakkaru of the time of Ramses III. Thereafter the Egyptian records are silent as to the scattered tribes of Crete, just as they had been silent since the rise of the Nineteenth Dynasty as to the organized Empire of the Keftians. The eleven shiploads of Zakru sea-robbers are the last degenerate representatives of the great marine which, under the Kings of the House of Minos, had once held the undisputed Empire of the AEgean. The ring of Minos was destined to lie for long ages beneath the waves before the descendants of Theseus brought it up again. CHAPTER IX THE PERIODS OF MINOAN CULTURE We must now endeavour to form some idea of the various periods into which the long enduring culture of the Minoan Empire more or less naturally falls, and to note some of the characteristic features of each period. The chief aid in the formation of such an idea is given by the remains of the pottery which have survived from each period, and it is largely from the classification of the pottery at Knossos and other sites that the scheme adopted by Dr. Evans and other workers has been derived. The deposit left by Neolithic man on the hill of Kephala averages about 6 metres in thickness below the later deposit which marks the occupation of the site by the post-Neolithic culture. We are thus led to an almost fabulous antiquity for the first occupation of the site. In the earliest beginnings of human development, progress, with its consequent accumulation, is slow, and if we allow a rate of 3 feet of deposit for each thousand years, we shall probably not be very far wrong. Such an allowance brings us to about 10,000 B.C. as the time when Neolithic man began his first settlement on the hill of Knossos.