This leads us to wonder whether these broad-heads belonged to wanderers from Anatolia, or whether it is not more probable that here we have evidence of the arrival of the Prospectors, who seem always to be the organisers of oversea trade and of mining operations. We must remember too, that by 2800 /B.C./, not long after the beginning of the Early Minoan period, the Sumerians were trading in the Mediterranean, and knew, if they had not already settled in, Crete.[367] These are details of which we cannot speak with certainty at present, but all the isolated data available are best explained by believing that the great activities of the trade in the Ægean and especially in Crete were organised by and were in the hands of Prospectors, who had come originally, though not necessarily directly, from the Persian Gulf, and who were employing the Mediterranean aborigines as mariners, miners and craftsmen. When in Middle and Late Minoan times these Cretans made settlements on the mainland, in the Argolid, in Bœotia, and at Pylos, settlements which are recorded in the legends of Danaus, Cadmus and Neleus, we can well believe that, while some of their subjects were of the Mediterranean race, and others, perhaps, drawn from the Alpine aborigines of the mainland, the rulers were in all cases Prospectors. Professor Ure[368] has recently shown us that in Greek lands, as well as in renaissance Italy, we find two types of rulers, who may be described as Kings and Tyrants. The king is a military chief, of aristocratic bearing and origin, and one more often interested in the territory than in the city. The tyrant, on the other hand, is essentially a merchant or a business man, his outlook bourgeois, and he rules over a city and its trading connections, rather than over a wide expanse of land. In Greece, Ure believes, the introduction of metal currency caused the earlier kings to be replaced by these tyrants or merchant princes. He has supported his thesis by a vast mass of evidence, which we need not repeat here, but in his conclusions I think we may see the supplanting of the Nordic lord by the Prospector, as times became more settled and trade, rather than fighting, became the more important occupation. Many of Ure’s arguments would apply equally to the Minoan age, when piracy had been put down and oversea trade was booming. The rise of the Greek tyrants was due, he thinks, to the rise of a coinage, just as the modern plutocrat has risen to power on the development of paper currency; the Minoan tyrant, comes to the front as metal, an easily portable and exchangeable commodity, succeeds flint or obsidian. It was into these trading cities, each governed by a Prospector tyrant, that I believe these Nordic “Achæan” adventurers to have arrived from the Danube basin with their leaf-shaped swords.