Leukon I

The cities of Theodosia and Chersonesus.

After his father's death and his ascendance to the throne, Leukon laid siege the city of Theodosia twice. The first siege ended in a Bosporan defeat due to Tynnichus, a general sent by Heraclea Pontica, to relieve the city, which he accomplished, despite inferior numbers, due to trickery.[12]

Leukon besieged Theodosia again 5 years later in a surprise attack, before the city could receive relief aid from the Heracleotes. It is possible that the Heracleotes withdrew before Leukon attacked due to a change of government from oligarchy to tyranny under Clearchus.

He was then attacked by the Heracleotes in his own territory. Leukon, noticing that his own troops could be routed easily,[13] positioned his Scythian soldiers in the rear and gave clear instructions that his men were to be struck down if they fled.[14] This precaution helped his army defeat the Heracleotes.[15] Shortly after his victory, Leukon made a peace treaty with the Heracleotes, ending the war.

Leukon then turned his eye to the Sindike Kingdom, where there had been a dynastic dispute between Hekataios, the king of Sindoi, and his son, Oktamasades who had taken power from his father. Before the Battle of Labrytai, Leukon said he “made a vow to erect a victory monument, but not to the local Apollo of Labrys, but to the supreme deity and patron of all the Bosporans, Apollo the Healer”.[16] After defeating Oktamasades, it is possible Leukon persuaded Hekataios to give the kingship over to him, as Leukon was proclaimed "king of all the Sindike" shortly thereafter.

During the probable last years of Leukon's reign, it is possible that Heraclea Pontica had hired Memnon of Rhodes, the famous guerrilla fighter who had fought Alexander. Heraclea Pontica sent envoys to Leukon to learn the size of his army.[17] Upon hearing that there were not many soldiers, Memnon went to battle Leukon, and used trickery to gain an easy victory against the Bosporan army. Memnon had his army march over to a hill, leaving only half of his men visible, as if to show that there was desertion amongst his troops.[18] He then dispatched a "deserter"[19] to inform the Bosporan army that there had been a mutiny in the Heracleote army.[20] The Bosporan forces marched out to Memnon's forces, believing that they had been split in half, but were defeated as in reality the army was completely intact.[21]

Leukon was well regarded by the Athenians, as the Bosporan Kingdom exported a large portion of their grain primarily to Athens. On one occasion, when Athens could not make do on their payment because of restrictions Sparta had placed on them during the Peloponnesian War, he gave them 400,000 medinmoi of grain which is around 16,380 t,[22] free of charge in 356 BC. For this, Leukon was praised in Athens and was both given citizenship and statues of him and his sons erected in Athens. His descendants such as Spartokos III, who gave Athens 15,000 medimnoi of grain (ca 590 t) as a gift.[23] They would continue to follow this diplomatic friendship with the Athenians. Leukon also gave Athenian ships privileges at his ports and did not have them taxed when they docked.

Leukon died in 349 BC, after a reign of around 40 years, he was at least 60 years old during the time of his death, placing his birth prior to or around 410 BC. His body is thought to have been placed in the Royal Kurgan,[24] a burial mound where the previous Bosporan rulers had been placed in, in the outskirts of Panticapaeum. Leukon's actions mirrored those of his grandfather, Spartokos I, who usurped the former Greek dynasty of the Bosporan state, as well as those of his father Satyros, whom he often credited with transforming Panticapaeum from a mere hegemony into an expansive kingdom on the Black Sea which would go on to be the longest-lasting Roman client-state for another 800 years. Leukon's descendants would rule the Bosporus for another two centuries—the last of whom, Paerisades V, would die during a Scythian uprising.