When, in the fourth century, wealth, ebbing on the Tiber, floated to the Bosphorus the core of the Latin aristocracy, it carried with it also the Latin coinage. For several generations this coinage underwent little apparent alteration, but after the final division of the Empire, in 395, between the sons of Theodosius, a subtle change began in the composition of the ruling class; a change reflected from generation to generation in the issues of their mints. Sabatier has described the transformation wrought in eight hundred years with the minuteness of an antiquary. If a set of Byzantine coins are arranged in chronological order, those of Anastasius, about 500, show at a glance an influence which is not Latin. Strange devices have appeared on the reverse, together with Greek letters. A century later, when the great decline was in progress under Heraclius, the type had become barbarous, and the prevalence of Greek inscriptions proves the steady exhaustion of the Roman blood. Another fifty years, and by 690, under Justinian II., the permanent and conventional phase had been developed. Religious emblems were used; the head of Christ was struck on the golden son, and fixity of form presaged the Asiatic domination. The official costumes, the portraits of the emperors, certain consecrated inscriptions, all were changeless; and in 717, an Armenian dynasty ascended the throne in the person of Leo the Isaurian.[77] This motionless period lasted for full three hundred and fifty years, as long as the exchanges of the world centred at Byzantium, and the monied race who dwelt there sucked copious nutriment from the pool of wealth in which it lay. But even before the crusades the tide of trade began to flow to the south, and quitting Constantinople passed directly from Bagdad to the cities of Italy. Then the sustenance of the money-changers gradually failed. From the reign of Michael VI. effigies of the saints were engraved upon the coin, and after the revolution led by Alexius Comnenus, in 1081, the execution degenerated and debasement began. This revolution marked the beginning of the end. Immediately preceding the crusades, and attended by sharp distress, it was probably engendered by an alteration in the drift of foreign exchanges. Certainly the currency contracted sharply, and the gold money soon became so bad that Alexius had to stipulate to pay his debts in the byzants of his predecessor Michael.[78] For the next hundred years, as the Italian cities rose, the Empire languished, and with the thirteenth century, when Venice established its permanent silver standard by coining the “grosso,” Constantinople crumbled into ruin.