Sophos is the protegé of the Magus of Sounis and the nephew of the King of Sounis. Since Sounis has no children of his own, Sophos is the king's heir presumptive. His father is a duke and the illegitimate half-brother to the King of Sounis; the King's legitimate brothers all died under mysterious circumstances. He is a supporting character in The Thief and the protagonist of A Conspiracy of Kings.