Sosibius of Tarentum in the context of Ptolemy II of Egypt

Taranto (Italian: [ˈtaːranto] ; Tarantino: Tarde), historically also called Tarent in English, is a coastal city in Apulia, Southern Italy. It is the capital of the province of Taranto, serving as an important commercial port as well as the main Italian naval base. With a population of 185,909 as of 2025, Taranto is the second-largest city in Apulia.

Founded by Spartans in the 8th century BC during the period of Greek colonisation, Taranto was among the most important poleis in Magna Graecia, becoming a cultural, economic and military power that gave birth to philosophers, strategists, writers and athletes such as Archytas, Aristoxenus, Livius Andronicus, Heracleides, Iccus, Cleinias, Leonidas, Lysis and Sosibius. By 500 BC, the city was among the largest in the world, with a population estimated up to 300,000 people. The seven-year rule of Archytas marked the apex of its development and recognition of its hegemony over other Greek colonies of southern Italy.

Sosibius (Ancient Greek: Σωσίβιoς; floruit 221-204 BC) was the chief minister of Ptolemy IV Philopator (221–204 BC), king of Egypt. Nothing is known of his origin or parentage, though he may have been a son of Sosibius of Tarentum; nor is there any account of how he rose to power. He is first attested immediately after the accession of Ptolemy IV in 221 BC, exercising great influence over the 22-year old king alongside Agathocles, the brother of Ptolemy IV's mistress Agathoclea. He remained a major force throughout the reign and helped ensure the smooth succession of Ptolemy V Epiphanes in 204 BC. After that he disappears from the record.