He was a great city builder founding amongst many other cities teh famous Tetrapolis of Antioch Apamea Laodicea and Seleucia.
As with many other dynasties the first two or three rulers were excellent but then there was a decline.
Seleucus Nicator the first shown above started off controlling a vast area of Asia from the Mediterranean coast across to the Indus valley. He traded off the far eastern section of his realm for trained Indian war elephants.
Persia and other areas were lost to the Parthians but the Seleucid empire had a brief revival and expansion westwards under Antiochus the 3rd who conquered Greece but defeated lost all the lands west of the Taurus mountains.
One of the most interesting queens of the Seleucid dynasty mother and wive to several of them was another Cleopatra, Cleopatra Thea a Ptolemid princess.
Faced with the Roman advance to the West and the rise of the Parthians to the East Seleucid dynasty sadly declined destroying itself with internal conflcit between various heirs and pretenders and cousins until its realm was little more than Syria and the two final rulers was slain by Pompey.
Syria became a Roamn province and is now once again being fought over but the Seleucids left a legacy of city building and Antioch still stands today.