1. The kingdom of the Seleucidae was founded in Upper Asia by Seleucus Nicator. It was an extensive empire; but, being composed of various countries united only by conquest, it could possess but little internal stability except what it derived from the power of its rulers. That power fell with the founder; and the transfer of the seat of empire from the banks of the Tigris to Syria, entangled the Seleucidae in all the political disputes of the western world, and facilitated the insurrection of the upper provinces. The history of this kingdom divides itself into the periods before and after the war with Rome; although at the breaking out of this war the seeds of its decline and fall had already been sown. Seleucus received, 321, Babylon as his province; but after the defeat of Eumenes was obliged to take to flight, 315, in order to avoid subjection to the conqueror Antigonus. But his moderate government had rendered him so popular, that after the victory won by Ptolemy over Demetrius at Gaza, 312, he could safely venture to return with only a few adherents to Babylon. In this year commences the kingdom of the Seleucidae. 2. In the ten following years, and while Antigonus was busied in Asia Minor, Seleucus laid the foundation of his power over all Upper Asia, with a facility to which the detestation excited by the rigid government of Antigonus mainly contributed. After his victory over Nicanor of Media, all in that quarter declared spontaneously for him; and the unsuccessful expedition of Demetrius taught Antigonus himself, that it would no longer be prudent to assert his claims. As early as 307, Seleucus was in possession of all the countries between the Euphrates, Indus, and Oxus. 3. Great campaign in India undertaken by Seleucus against king Sandracottus. He penetrated as far as the Ganges, and the close alliance he formed with the Indian sovereign lasted a long time after, and was kept up by embassies. The great number of elephants which he brought back with him was not the only advantage accruing from this expedition; the intercourse with the east seems to have been permanently reestablished. 4. By the battle of Ipsus Seleucus added to his dominions the greater part of the territories of Antigonus;--Syria, Cappadocia, Mesopotamia, and Armenia. Unfortunately Syria now became the head province, notwithstanding Coele-Syria and Phoenicia were left in the hands of Ptolemy. How widely different would have been the course of historic events, had the seat of empire remained at Seleucia on the Tigris, and the Euphrates continued to be the western boundary of the Seleucidae! 5. Reciprocal relations between the several kings, who now combine in forming a kind of political system, in which continued exertions to maintain a balance of power by alliance and marriage are plainly discernible.