Ptolemy; died 333 BC) son of Seleucus from Orestis or Tymphaia, was one of the select officers called Somatophylaces, or guards of the king's person; he combined with that distinguished post the command of one of the divisions of the phalanx

Phalanx formation

The phalanx is a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar weapons...

. Ptolemy was from an upper noble family. His brother was a distinguished general called Antiochus

Antiochus (father of Seleucus I Nicator)

Antiochus was a Macedonian man that lived during the time of Philip II of Macedon, who ruled from 359 BC-336 BC. He originally came from Orestis, Macedonia....

, hence was the paternal uncle to Seleucus I Nicator

Seleucus I Nicator

Seleucus I was a Macedonian officer of Alexander the Great and one of the Diadochi. In the Wars of the Diadochi that took place after Alexander's death, Seleucus established the Seleucid dynasty and the Seleucid Empire...

 and his sister Didymeia

Didymeia (sister of Seleucus I Nicator)

Didymeia was a Greek Macedonian noblewoman. She originally came from an upper Macedonian noble family. Didymeia was the daughter of...

. He was lately married when he accompanied Alexander on his expedition to Asia, 334 BC, on which account he was selected by the king to command the body of Macedon

Macedon

Macedonia or Macedon was an ancient kingdom, centered in the northeastern part of the Greek peninsula, bordered by Epirus to the west, Paeonia to the north, the region of Thrace to the east and Thessaly to the south....

ians, who were allowed to return home for the winter at the end of the first campaign. In the following spring he rejoined Alexander at Gordium

Gordium

Gordium was the capital city of ancient Phrygia. It was located at the site of modern Yassıhüyük, about 70–80 km southwest of Ankara , in the immediate vicinity of Polatlı district. The site was excavated by Gustav and Alfred Körte in 1900 and then by the University of Pennsylvania Museum,...

, with the troops under his command, accompanied by fresh reinforcements. At the Battle of Issus

Battle of Issus

The Battle of Issus occurred in southern Anatolia, in November 333 BC. The invading troops, led by the young Alexander of Macedonia, defeated the army personally led by Darius III of Achaemenid Persia in the second great battle for primacy in Asia...

 (333 BC) his division of the phalanx was one of those opposed to the Greek

Ancient Greece

Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

 mercenaries under Darius III

Darius III of Persia

Darius III , also known by his given name of Codomannus, was the last king of the Achaemenid Empire of Persia from 336 BC to 330 BC....

, and upon which the real brunt of the action consequently devolved; and he himself fell in the conflict, after displaying the utmost valour.