After this Scyles rode off to his own place; but the Scythians rebelled against him, setting up his brother Octamasades, son of the daughter of Teres, for their king. [2] Scyles, learning what had happened concerning him and the reason why it had happened, fled into Thrace; and when Octamasades heard this he led his army there. But when he was beside the Ister, the Thracians barred his way; and when the armies were about to engage, Sitalces sent this message to Octamasades: [3] “Why should we try each other's strength? You are my sister's son, and you have my brother with you; give him back to me, and I will give up your Scyles to you; and let us not endanger our armies.” [4] Such was the offer Sitalces sent to him; for Sitalces' brother had fled from him and was with Octamasades. The Scythian agreed to this, and took his brother Scyles, giving up his own uncle to Sitalces. [5] Sitalces then took his brother and carried him away, but Octamasades beheaded Scyles on the spot. This is how closely the Scythians guard their customs, and these are the penalties they inflict on those who add foreign customs to their own.