Seleucus I (given the surname by later generations of Nicator, i.e.

Seleucus the Victor) (ca.

358 BCE – 281 BCE) is a Macedonian officer of Alexander the Great and one of the Diadochi.

In the Wars of the Diadochi that take place after Alexander's death, Seleucus establishes the Seleucid dynasty and the Seleucid Empire.

His kingdom will be one of the last holdouts of Alexander's former empire to Roman rule.

They are only outlived by the Ptolemaic Kingdom in Egypt by roughly 34 years.

After the death of Alexander, Seleucus is nominated as the satrap of Babylon in 320 BCE.

Antigonus forces Seleucus to flee from Babylon, but, supported by Ptolemy, he is able to return in 312 BCE.

Seleucus' later conquests include Persia and Media.

It is assumed that he was defeated by the emperor of India, Chandragupta Maurya and accepted a matrimony alliance for 500 elephants after ceding the territories considered as part of India.

Seleucus defeated Antigonus in the battle of Ipsus in 301 BC and Lysimachus in the battle of Corupedium in 281 BC.

He is assassinated by Ptolemy Ceraunus during the same year.

His successor is his son Antiochus I. Seleucus founds a number of new cities, including Antioch and Seleucia.