Seleucus I (ca. 358-281 B.C.), a Macedonian general, was a Companion of Alexander the Great, king of Babylonia and Syria, and founder of the Seleucid empire and dynasty.
The son of a Macedonian nobleman, Seleucus was born between 358 and 354 B.C. in Macedonia, then ruled by Philip II. He grew up with the king's son, Alexander, and became Alexander's close associate during his expedition through Persia. Seleucus was present with Alexander at Susa in 324, and according to Alexander's bidding, Seleucus married the Bactrian princess Apama. Unlike many of the Macedonians, Seleucus never repudiated this political marriage.
When Alexander died in 323, Seleucus ranked well below the leading "successors." The kingship went jointly to Alexander's epileptic and half-witted half brother, Philip Arrhidaeios, and the unborn child carried by Alexander's Bactrian wife, Rhoxana. Perdikkas, the leading general and Macedonian nobleman in Babylon, became their regent. Of the other prominent generals, Ptolemy sought the satrapy of Egypt; Antipater remained in Greece as governor and, allied with Craterus, crushed the Athenian rebellion; Lysimachus obtained Thrace; and Antigonus "the One-eyed" gained the powerful satrapy of Phrygia.
Opposition arose to Perdikkas, and in 321 war erupted. Caught between the northern powers and Ptolemy to the south, Perdikkas divided his forces. Seleucus, who had received no lands or personal power other than a generalship under Perdikkas, supported the regent. Perdikkas and Seleucus marched against Ptolemy and three times failed to cross the Nile Delta.
Seleucus, wishing to overthrow his perpetual subordination, turned on Perdikkas and joined in his assassination. Consequently, Seleucus gained the satrapy of Babylonia and the power he sought. Although the satrapy of Babylonia remained the heart of Alexander's empire, Seleucus found the borders difficult to maintain. In Asia Minor, Antigonus rapidly gained more power, and leaders in Media and Susiana also sought to overthrow Seleucus.
When Antipater, the new royal regent, died in 319, Antigonus sought greater power and larger realms. In 321 Antipater had appointed Antigonus commander of the royal armies in Asia, and Antigonus desired to reunite Alexander's empire. When royalist uprisings in Asia threatened Seleucus's insecure power, out of necessity he summoned Antigonus's assistance. Once in Babylonia, Antigonus assumed supreme command and reduced the royalists, and in 316 Seleucus fled to Egypt and Ptolemy's protection. Together, Ptolemy, Cassander (the son of Antipater), and Lysimachus opposed Antigonus and demanded that Seleucus be restored to Babylonia. By 311, with Antigonus back in Asia Minor, Seleucus and Ptolemy entered Palestine. The victorious Seleucus headed for Babylon, gaining the support of the people, the armies, and minor officials. From 311 on, Seleucus retained Babylonia. Pushing eastward Seleucus rapidly conquered the once rebellious Media and Susiana. Antigonus, however, remained a threat and regained Palestine.
In 311 Seleucus founded Seleucia on the Tigris as his new capital. It replaced ancient Babylon and became an eastern outpost of Greek civilization—a major entrepôt blending Greeks, Babylonians, and Jews. With the Chaldean Magi, Seleucus also founded the eastern city of Ctesiphon across the Tigris from Seleucia.
During the next 9 years Seleucus strengthened his eastern borders and crossed the Indus River and invaded India. In the west Antigonus still dominated and in 305 assumed the royal title. In Babylonia, Seleucus ruled a tight, efficient government modeled upon the earlier Persian absolutism. He developed his army and the bureaucracy and built new cities during a humane and able kingship.
In 302 Seleucus marched against Antigonus and entered Phrygia. In the following spring he allied once again with the "separatist generals" Ptolemy, Cassander, and Lysimachus, and at Ipsus in a heated battle he defeated and killed Antigonus. As booty, Seleucus obtained Syria. Seleucus thus gained the chief military and political position among the kings, which caused an estrangement with them. In Syria he built Antioch-on-the-Orontes in 300. Seleucus's son by Apama, Antiochus (I), ruled as viceroy of the dominions east of the Euphrates. Seleucus's love for Antiochus was such that he divorced his second wife, Stratonice, in 293 to allow his son to marry her.
In 293 Seleucus occupied Cilicia in eastern Asia Minor and began to plot against Demetrius (his former father-in-law), who had seized the Macedonian throne. Seleucus once again allied himself with Ptolemy and Lysimachus. Lysimachus, however, took Macedonia for himself, and Seleucus turned against him. In the spring of 281 Seleucus set out to conquer Asia Minor and to defeat Lysimachus. With him was the eldest son of Ptolemy I, Ptolemy Keraunos, who continually intrigued against his father and against Seleucus. The aged Ptolemy I failed to aid Lysimachus, who fell to a traitor's spear. But when Seleucus advanced on Macedonia that summer, Ptolemy Keraunos stabbed him to death in a vain attempt to claim the Macedonian throne.
Edwyn Bevan, The House of Seleucus (2 vols., 1902), remains the major study of Seleucus and the Seleucid dynasty. General studies of the Hellenistic era are W. W. Tarn and G. T. Griffith, Hellenistic Civilization (1927; 3d rev. ed. 1952), and Pierre Grimal and others, Hellenism and the Rise of Rome (1968).