 Seleucid attempts to defeat their old enemy Ptolemaic Egypt were frustrated by Roman demands.Having come into conflict in the east (305 BC) with the Maurya Empire, Seleucus I entered into an agreement with its leader, Chandragupta, whereby he ceded vast territory west of the Indus, including the Hindu Kush, modern-day Afghanistan, and the Balochistan province of Pakistan and offered his daughter in marriage to the Maurya Emperor to formalize the alliance.Antiochus III the Great attempted to project Seleucid power and authority into Hellenistic Greece, but his attempts were thwarted by the Roman Republic and by Greek allies such as the Kingdom of Pergamon, culminating in a Seleucid defeat at the 190 BC Battle of Magnesia.