The Seleucid Empire, founded in 323 B.C.E. by [Seleucus I]?, controlled a large region including Mesopotamia, Persia (eastward to the Indus River), modern-day Syria, Lebanon, and Jordan. The Selecuid Empire lost much territory just prior to and during the 2nd century B.C.E; Gedrosia? on the coast of the Arabian Sea and Arachosia? on the west bank of the Indus were ceded to Chandragupta? in 303 B.C.E.; Bactria? asserted independence in 250 B.C.E., followed by Parthia ten years later. [Antiochus III]? is considered the greatest of the Seleucid monarchs, but his campaigns in Greece in 192 B.C.E. attracted the attention of the Roman Empire, after which the Seleucids declined.