Seleucid Empire - Rise of Seleucus

Rise of Seleucus

Alexander's generals (the Diadochi) jostled for supremacy over parts of his empire. Ptolemy, a former general and the satrap of Egypt, was the first to challenge the new system; this led to the demise of Perdiccas. Ptolemy's revolt led to a new subdivision of the empire with the Partition of Triparadisus in 320 BC. Seleucus, who had been "Commander-in-Chief of the camp" under Perdiccas since 323 BC but helped to assassinate him later, received Babylonia, and from that point continued to expand his dominions ruthlessly. Seleucus established himself in Babylon in 312 BC, the year used as the foundation date of the Seleucid Empire. He ruled not only Babylonia, but the entire enormous eastern part of Alexander's empire:

"Always lying in wait for the neighboring nations, strong in arms and persuasive in council, he acquired Mesopotamia, Armenia, 'Seleucid' Cappadocia, Persis, Parthia, Bactria, Arabia, Tapouria, Sogdia, Arachosia, Hyrcania, and other adjacent peoples that had been subdued by Alexander, as far as the river Indus, so that the boundaries of his empire were the most extensive in Asia after that of Alexander. The whole region from Phrygia to the Indus was subject to Seleucus." — Appian, The Syrian Wars

Seleucus went as far as India, where after two years of war he reached an agreement with Chandragupta Maurya, in which he exchanged his eastern territories for a considerable force of 500 war elephants, which would play a decisive role at Ipsus (301 BC).

"The Indians occupy some of the countries situated along the Indus, which formerly belonged to the Persians: Alexander deprived the Ariani of them, and established there settlements of his own. But Seleucus Nicator gave them to Sandrocottus in consequence of a marriage contract, and received in return five hundred elephants." —Strabo, Geographica