King Miraz is the (former) main antagonist in The Chronicles of Narnia: Prince Caspian. He is voiced by Sergio Castellitto. He is also the unrightful ruler of Narnia. He reigns during the revisit of the Pevensie children and the second conquest of Narnia, and the conquerors being the Telmarines, who captured the anarchy-ridden land after the disappearence of the Pevensies.
The Chronicles of Narnia: Prince Caspian
Usurping the Throne
Miraz was the younger brother of Caspian IX, the king of Telmarine-Narnia and father of Caspian X. Miraz murdered his brother to take control of the throne. He let his nephew live because at the time, he had no heir himself.
He had Caspian's Nurse|a nurse raise Caspian in his early years, but dismissed her because Caspian unwittingly told him she was telling him stories of Narnia before the Telmarines invaded the country. He had a doctor named Doctor Cornelius teach Caspian from that point on. What Miraz didn't know was that Cornelius was actually half-dwarf, and was also telling Caspian about the Old days of Narnia.
Miraz's wife, Queen Prunaprismia, eventually gave birth to a son when Caspian was a young man. No longer needing Caspian, he planned to have him killed. But Caspian had been warned about this by Dr.Cornelius and fled for his life. While on the run, he met with the Old Narnians and promised to lead them in an attempt to overthrow Miraz and the Telmarine dynasty. Miraz learned of this, and sent armies forth to quell his nephew and his army of Old Narnians during their revolution. During this time, the four Pevensies returned to Narnia (due to Caspian blowing Susan's Horn), and they allied with Caspian. Miraz's dueled against Peter Pevensie before the Second Battle of Beruna. During this time, one of his own lords, Sopespian, stealthily stabbed him in the back with an arrow and blamed it on the Narnians. The battle that followed resulted in the fall of the Telmarine dynasty.
Miraz was a proud man, though he was also cruel and evil. He was willing to betray and kill his own brother to take the throne, and was only willing to let Caspian take his place as king as long as he had no other heir.