The short blonde red eyed mf is the duke. The big gray haired mf is a royal. Probably related to the king in some way (didnt catch what wat either). The long haired blonde with purple eyes is the king aka price's dad.
Maybe part of your confusion stems from who holds power in this kingdom. Ordinarily it should be the king, but not in this world: the round table basically runs the kingdom with the king as a figurehead to the people. The red eyed duke seems to be the most callous and influential of the round table who controls all affairs relating to the court and dragon royal line. The king was ordered (?) to enter the forest with his regas as a test, even though he was unwilling, which goes to show that level of control and the king's powerlessness.
Hi! Just want to ask for clarification. I'm really confused who is who among the characters. Who is the King? Is it the one who always talk to Abel and Melmont with blonde hair? Who is the grayed hair old man with gold eyes (I'm guessing this is the prince's father?) And I'm chapter 16 who is the one who entered the forest (blonde eyes, purple eyes) I'm really lost who is HIS MAJESTY the King.