Nanda Empire
Prior to his consolidation of power, Alexander the Great had invaded the North-West Indian subcontinent before abandoning his campaign in 324 BCE due to a mutiny caused by the prospect of facing another large empire, presumably the Nanda Empire. Chandragupta defeated and conquered both the Nanda Empire, and the Greek satraps that were appointed or formed from Alexander's Empire in South Asia. Chandragupta first gained regional prominence in the Greater Punjab region in the Indus. He then set out to conquer the Nanda Empire centered in Pataliputra, Magadha. Afterwards, Chandragupta expanded and secured his western border, where he was confronted by Seleucus I Nicator in the Seleucid-Mauryan War. After two years of war, Chandragupta was considered to have gained the upper hand in the conflict and annexed satrapies up to the Hindu Kush. Instead of prolonging the war, both parties settled on a marriage treaty between Chandragupta and Seleucus I Nicator.