The war between Chandragupta Maurya and Seleucus was described by —

Megasthenes served as the ambassador of Seleucus I Nicator at the court of Chandragupta Maurya and wrote the Indica, known today mainly through quotations and summaries in later classical authors. This question belongs to the political, religious and diplomatic history of the Mauryan age. A sound answer requires matching the ruler, person, place, title or event with its correct chronological and documentary setting. Mauryan history is reconstructed from several different bodies of evidence: Ashokan inscriptions, archaeological remains, the Arthashastra tradition, Buddhist and Jain narratives, Puranic genealogies, and Greek or Roman accounts. These sources were produced at different times and for different purposes, so their claims should not automatically be treated as identical in reliability.