Seleucus, one of Alexander's generals, became satrap of Babylonia in 321 BC. The Seleucid empire stretched at one time from Thrace to India.  He was assassinated by the disgruntled son of Ptolomy in 281 BC.
The kingdom was a major center of Hellenistic culture and maintained the pre-eminence of Greek customs and manners over the Middle East. It began to decline in 190 BC after a first defeat by the Romans and lasted until 64 BC. Two cities in Syria are named after Seleucus' mother, Laodice - Lattakia - and his wife - Apamea.