Chandragupta Maurya
War and marriage alliance with Seleucus

According to Appian, Seleucus I Nicator, one of Alexander's Macedonian generals who in 312 BCE established the Seleucid Empire with its capital at Babylon, brought Persia and Bactria under his own authority, putting his eastern front facing the empire of Chandragupta. Seleucus and Chandragupta waged war until they came to an understanding with each other. Seleucus married off his daughter, Berenice, to Chandragupta to forge an alliance.

R. C. Majumdar and D. D. Kosambi note that Seleucus appeared to have fared poorly after ceding large territories west of the Indus to Chandragupta. The Maurya Empire added Arachosia (Kandahar), Gedrosia (Balochistan), and Paropamisadae (Gandhara). According to Strabo, Seleucus Nicator gave these regions to Chandragupta along with a marriage treaty, and in return received five hundred elephants. The details of the engagement treaty are not known. However, since the extensive sources available on Seleucus never mention an Indian princess, it is thought that the marital alliance went the other way, with Chandragupta himself or his son Bindusara marrying a Seleucid princess, in accordance with contemporary Greek practices to form dynastic alliances. An Indian Puranic source, the Pratisarga Parva of the Bhavishya Purana, described the marriage of Chandragupta with a Greek (" Yavana ") princess, daughter of Seleucus.

Chandragupta sent 500 war elephants to Seleucus, which played a key role in Seleucus' victory at the Battle of Ipsus. In addition to this treaty, Seleucus dispatched Megasthenes as an ambassador to Chandragupta's court, and later Antiochos sent Deimakos to his son Bindusara at the Maurya court at Patna.
combination:repeat_prompt, change_case:english_capital