The prosperity of the north African nations, did not fail to excite the jealousy and cupidity of surrounding powers, and accordingly we find that all the great conquerors of the East formed plans for their subjection. The Persians after conquering Egypt sent an army which took and plundered Cyrene, but retired without proceeding farther. But another project was formed against their independence by a conqueror the most sagacious and successful who has ever yet appeared. Among the commentaries left by Alexander of Macedon, as recorded by Diodorus Siculus, (_Book_ xviii. _Chap._ 1.) was found a project for the "invasion and subjection of the Carthaginians, and others dwelling on the coasts of Africa, Spain and the adjacent islands; for which a thousand ships were to be built, in the ports of Phoenicia, Syria, Cilicia and Cyprus, larger than those of three tiers of oars; with directions for carrying a straight and easy road along the shore of the Mediterranean, from Egypt to the Pillars of Hercules." With such an armament, and such a leader, it is highly probable that the project could have been carried into effect; the Grecian colonies already acknowledged his power, he was therefore secure of finding friends in the most difficult part of the country, either for naval or land operations; and the efficiency of his political arrangements in all other cases, does not permit us to doubt, that he would have founded in north Africa, a permanent and substantial empire. But this was not to be; Alexander died in the early summer of life, and of those who shared his dominions, no one was alone able to carry such a project into effect, and each was too much engaged in securing his own part, for any operation to have been conducted in concert. While the designs of Carthage were advancing towards fulfilment, she was gradually becoming a military state. Her fleets covered the sea, often transporting a hundred and fifty thousand combatants, and her armies of mercenary troops, led on by one of the most persevering and ingenious leaders of whom we have any account, overran an immense extent of territory, surmounting natural obstacles of the most appalling character, and overthrowing enemies celebrated for their skill and courage. But her commerce suffered, and the expenses of the war exhausted her treasury. Of the other African cities, many had declared and acted in favor of her enemies, while others were ready to desert her when a favorable opportunity should offer. The native tribes had acquired civilization sufficient to unite them, and to make them aware of their own importance; their chieftains had become ambitious, and Rome made offers to them which Carthage could never have advanced.