Which of Alexander's generals founded the Seleucid Empire?

Which of Alexander's generals founded the Seleucid Empire? Seleucus I Nicator founded it. After Alexander the Great died in 323 BCE, his generals—the Diadochi—fought over the enormous Macedonian Empire. Seleucus initially served as a commander under the regent Perdiccas, but after Perdiccas was assassinated, Seleucus became satrap of Babylon.

Antigonus I forced Seleucus out of Babylon, but Seleucus returned in 312 BCE with support from Ptolemy I Soter. His reconquest of Babylon is traditionally treated as the beginning of the Seleucid Empire and the Seleucid era. He then expanded eastward into Persia and westward after defeating Antigonus at Ipsus in 301 BCE.

The empire eventually covered much of the Near East, including Mesopotamia, Syria, Persia, and parts of Anatolia. Seleucus founded major cities such as Seleucia on the Tigris and Antioch. A common mix-up is confusing him with the other Diadochi: Ptolemy founded the Ptolemaic Kingdom in Egypt, while Cassander and Lysimachus ruled other successor territories. Seleucus was assassinated in 281 BCE and succeeded by his son Antiochus I.