He was present during his father's unsuccessful war against the barbarian queen Tirgatao of the Ixomatae, where his brother Metrodoros died as a hostage.
[8] Leucon also faced early problems with his subjects; he had to enlist the aid of merchants to successfully put down a rebellion fomented by some members of his court and even trusted friends.
Leucon, 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.
Leucon then turned his eye to the Sindike Kingdom, where there had been a dynastic dispute between Hecataeus, the king of the Sindi, and his son, Octamasades who had taken power from his father.
[16] After defeating Octamasades, it is possible Leucon persuaded Hecataeus to surrender the kingship to him, as he was proclaimed "king of all the Sindike" shortly thereafter.
Probably during the last years of Leucon's reign, Heraclea Pontica may have hired Memnon of Rhodes, the famous guerrilla fighter who had fought Alexander.
In 356 BC, 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 (around 16,380 t)[22] free of charge.
His body is thought to have been placed in the Royal Kurgan,[24] a burial mound where the previous Bosporan rulers had been interred, on the outskirts of Panticapaeum.
Leucon's actions mirrored those of his grandfather, Spartocus I, who usurped the former Greek dynasty of the Bosporan state, as well as those of his father Satyrus.