1. Which realms/kingdoms were the nine men kings of? And...
2. What makes the Witch King the head of the Nine? Why is he so special/more powerful?
What seems to be a simple question sometimes has to claim a chunk of space to answer. And when we deal with mythological and archetypal figures we move beyond what the author wrote. And then we enter the commercial applications and the dimensions can increase even more! And the fact is there is never a complete answer to the questions you have asked.
So what I will give you, and humbly ask you to accept, is a mixed answer with references ... I do this to give you a few resources which can provide greater understanding than the scholastic overview this humble one presents ... frankly it is hours of work and I am tired ... but I thank you for the inspiration to pursue this ... I learned a lot ...
The Nazgűl (from Black Speech nazg, "ring", and gűl, "wraith, spirit" (presumably related to gul, "sorcery");
An Elvish name given for the Ringwraiths is Ulairi. Linguists have remarked that it is a Quenya plural name of unknown meaning and etymology. Among their many names and titles were: the Ringwraiths, the Black Riders, the Fell Riders, the Nine Riders, the Black Wings, the Shadows, the Nine, the Nine Servants of the Lord of the Rings, and the Shriekers.
Their leader was the Witch-king of Angmar, and his second in command was named Khaműl. Khaműl was a lord of Easterlings. Three of the wraiths (including The Witch-king were high ranking Númenóreans. Khaműl is the only one of the Nazgul whose personal name is given by Tolkien The names of the other eight Nazgul are not known. However the following names for the other eight Nazgul were created for a role-playing game by Iron Crown Enterprises: Murazor (the Lord of the Nazgul), Dwar, Ji-Indur, Akhorahil, Hoarmurath, Adunaphel, Ren, and Uvatha. However, these names do not appear anywhere in Tolkien's works.
Your question about the Witch-king of Angmar is a book within itself. And it is one with many twists and much speculation. (but I will give it my best) The Witch-king of Angmar was the chief of the Nazgűl, King of Angmar, and Sauron's great captain in his wars. A wraith, the Witch-king of Angmar was nearly indestructible, a terrible warrior, and a cunning strategist. He was known by many names; * Witch-king of Angmar - "Witch" most likely coming from his background in sorcery, and "king" after his establishment of the realm of Angmar in 1300. * Witch-lord of Angmar - A variant of the above title. * Lord of the Nazgűl * Lord of the Ringwraiths * Chieftain of the Ringwraiths * Lord of the Nine Riders * King of the Nine Riders * Wraith-lord * Wraith-king * High Nazgűl * Lord of Morgul * Morgul-lord * King of Minas Morgul * Black Captain * Captain of Despair * Dwimmerlaik * Lord of Carrion Some time after Sauron seized the Rings of Power in the Sack of Eregion, S.A. 1697 he gave nine of them to Mannish kings, sorcerers, and other warriors. With these rings the Nine achieved glory and grew wealthy, with the ability to turn invisible at will, not aging, but hating life as they were slowly drawn under Saurons dominion. Eventually all became Ringwraiths, the dreaded Nazgűl. The one later known as the Witch-king was one of these, likely one of the unnamed three lords of Númenor to take the rings. He first appeared in the histories as a Ringwraith in S.A. 2251. Being the most powerful of the Nazgűl, he became their chief, the most dreaded servant of his master Sauron. When Mordor fell in S.A. 3441, the Nazgűl vanished into the shadows, and were not heard of again for a long time. More than a thousand years later, in c. 1050 of the Third Age, Sauron began to rebuild his power in Dol Guldur. In c.1300 his Nazgűl also reappeared, and the Witch-king established his realm, Angmar, in the north. His capital was Carn Dűm, on the northernmost peak of the Misty Mountains. He summoned men, orcs, and other creatures of evil inclination to his banner. No one knew that he was actually a servant of the long-dormant Sauron, and few that he was a wraith.
In the north, disunity plagued the Dúnedain of Arnor. They had divided into three kingdoms, Cardolan, Rhudaur, and Arthedain, and were constantly at war with one another. The Witch-king saw the North-kingdom of Arnor as more vulnerable than the South-kingdom of Gondor. He played upon their opposition, sending in infiltrators and taking over the hearts of the men of that land. By 1349 the government of Rhudaur was controlled by men secretly in his service, and he secretly aided them in their wars against the other kingdoms. He then struck at a time of great hostility among the three, in 1409. Rhudaur in the east fell first, and most of the Dúnedain there were hunted down and slaughtered by sorcerers. Cardolan was ravaged, and the Tower of Amon Sűl, held by the men of Arthedain, was placed under siege. King Arveleg I was slain, and the tower was destroyed, but the coveted palantír escaped in the hands of the surviving men of Arthedain and was brought to Fornost.
The Witch-king continued to press the men of Arthedain, laying siege to Fornost, and he might have taken over all of Arnor in that one offensive. But Araphor, the 18-year-old son of Arveleg, came to leadership and, with the help of the ancient elf Círdan of Lindon, repelled the Witch-kings forces at Fornost and the North Downs. Elrond brought an army of Elves from Rivendell and Lothlórien, and the Witch-king was pushed back and subdued. The Witch-king sat silent in Carn Dűm, rebuilding his armies and preparing for a final assault on Arthedain, last of the Arnorian kingdoms. The Dark Plague came and went in 1636, taking with it the last of the Dúnedain of Cardolan. The Witch-king sent barrow-wights to inhabit the barrows in Tyrn Gorthad. In 1974, he felt that his power was sufficiently restored to begin the advance.
His attack was sudden, but not unexpected. King Arvedui sent a message to King Eärnil II of Gondor the year before, but help did not arrive in time. Fornost fell, and the Witch-king took up residence there in the palace. Arvedui held out as best as he might on the North Downs, but at last fled north with the treasured palantíri of Amon Sűl and Annúminas. He would not return, for he perished in a shipwreck in 1975. With him the palantíri were lost forever in the icy seas of Forod. The already-diminished North-kingdom ended, and Arnor fell.
Meanwhile, a coalition in the south had formed. Eärnil sent his son, Eärnur, north with a great fleet, all that Gondor could spare. They arrived at Lindon, and joined with the folk of Círdan. Círdan summoned all that would come: surviving Dúnedain of Arnor and elves of Lindon. Even a company of hobbit archers went to their aide. The Witch-king had grown overconfident, and instead of staying behind his fortifications initiated the attack. The Battle of Fornost was fought on the plain between Nenuial and the North Downs. The Witch-king may not have anticipated the strength brought against him, but for whatever reason the alliance gained the upper hand. His army began to fall back toward Fornost, but Eärnurs magnificent horsemen struck from the north, and the Witch-king was routed.
He decided to flee to Angmar and the safety of Carn Dűm, but the cavalry, with Eärnur himself in the lead, overtook him. Moreover, the ranks of the allies swelled, as an army of elves from Rivendell came led by the mighty hero of old, Glorfindel. Angmar was purged of men and orcs, and all seemed lost for the Witch-king in the face of such numbers. But the Witch-king himself came at the last, robed and masked in black and riding a black horse, and attempted to kill Eärnur with his own hands. But Eärnurs horse shied away and fled, and the Witch-king laughed. But Glorfindel came on his white horse, and faced with such power the Witch-king fled. He vanished into the shadows, and no-one marked where he had gone.
Eärnur wanted to pursue, but Glorfindel held him back, and made his famous prophecy. He will not return to this land. Far off yet is his doom, and not by the hand of man will he fall. - Glorfindel, (The Lord of The Rings, The Return of the King, Book Six, Appendix A)
The Witch-king escaped to Mordor, and gathered the other Ringwraiths about him in 1980. Angmar and Carn Dűm were lost, and so in 2000 the Witch-king began a two-year siege of Minas Ithil, eventually capturing the place and turning it into his residence. It was renamed Minas Morgul, and the palantír was sent to Sauron. The Witch-king sent an aura of fear in Gondor, and much of Ithilien was deserted.
Eärnur succeeded his father as King of Gondor, and still held the Witch-king in especial hostility due to his humiliation at the Battle of Fornost. The year of his coronation the Witch-king sent him a taunting challenge, but Mardil Voronwë the steward restrained Eärnur from rash action. Seven years later the challenge was repeated, and Eärnur rode with a small escort to Minas Morgul. None that rode thither ever returned, and there was no longer a King in Gondor.
After this the Witch-king bided his time. He and the Nazgűl built up their armies, including the terrible new orc-race of uruks. In 2475 he sent them out to capture Osgiliath, which they did successfully. They were driven out by Boromir, Steward of Gondor, but Osgiliath now lay completely in ruins. Boromir went on to retake Ithilien, so that even the Witch-king feared him. But he was killed by a Morgul-wound, and so his rule was but twelve years.
Sauron declared himself openly in 2951, and sent three of his Ringwraiths to Dol Guldur (though the Witch-king was left in Minas Morgul). Then, by lucky chance, the creature Gollum was captured and interrogated. Under torture, the wretched creature revealed the tale of the One Ring and how it came to be in his possession. But he had the daring to trick Sauron into thinking that the land of the hobbits who stole the Ring was on the banks of the Gladden River. Under the leadership of the Witch-king, Sauron sent the Nine unclothed and invisible to search for the Ring after the assault of Osgiliath.
Khaműl, the Witch-kings lieutenant, reported that he was unable to find the Shire in the vales of Anduin. The Witch-king was determined to search north and west until Gollum was found, or the Shire. But plans were halted when Sauron received word of the prophecy in Gondor and the doings of the turncoat Saruman, and concluded that the Wise did not yet have possession of the Ring. He sent the Ringwraiths to Isengard in the form of Black Riders, too late to prevent the escape of the captured wizard Gandalf, but had words with Saruman. Saruman, already a traitor to both sides due to his transparent lust for the Ring, fortified himself in Isengard. The Witch-king did not have enough power with him to assault Saruman in his great fortress, but had words with him. Saruman convinced the Witch-king that Gandalf alone knew where the Shire and the Ring was, and so the Nine passed into Rohan in search of him.
They came upon the traitor called Wormtongue and questioned him. The terrified man told them everything he knew; that Gandalf had passed through Rohan, where the Shire was, and even that Saruman had lied to them. The Witch-king spared Wormtongues life, foreseeing that Wormtongue would bring ruin to Saruman. He divided his wraiths into four pairs, and went with the swiftest to Minhiriath. Along the way they captured several spies of Saruman, and found to their delight charts and maps of the Shire. They sent along the spy to Bree, warning them that they now belonged to Mordor, not Saruman.
They came to Sarn Ford, but the Dúnedain Rangers prevented them from crossing. They sent for their great captain, the chieftain Aragorn II, who alone could well resist the wraiths, but he was away, and the Ringwraiths captured the ford and killed many of the Rangers. The Witch-king sent three Ringwraiths under Khaműl into the Shire while he went east with the others. But they had come too late: the Ring had moved on in the hands of a hobbit, Frodo Baggins.
Khaműl was unsuccessful, but brought word from the spy they had spared in Bree. The man had witnessed a vanishing act on Frodo's part, and had organized an attack on the inn. The Witch-king guessed that Frodo would head east, and sent four wraiths to Weathertop, the ruins of the tower he had destroyed long ago. He went south along the Greenway and discovered nothing. Gandalf followed them, but the Witch-king let him slip ahead, and attacked him on Weathertop. Gandalf escaped at dawn, and again the Witch-king divided his force and sent four after the wizard.
The Ring walked almost right into his hands. The captain of the Dúnedain, Aragorn II, had become the guide of the hobbits, and led them to Weathertop, where they were spotted and attacked. The Witch-king advanced on Frodo, and the terrified hobbit put on the Ring, seeing them as they truly were. When Frodo resisted, and invoked the name of Elbereth, the Witch-king stabbed Frodo in the shoulder. The tip of his blade broke off and sent poison through the hobbits veins. Then Aragorn counterattacked with flaming brands. The Witch-king fled at his mighty presence, confident that the poison of the blade would do its work and bend Frodo's will to his purpose. But he was shaken by the encounter; Gandalf and Aragorn were people of immense power, and even the Ring-bearer, who was not an especially strong person, had dared to resist him. He feared that Frodo might have some elvish power. Moreover, he knew that Frodos weapon, a blade of Westernesse, was wrought for his undoing and if it had struck him would have done him damage. He was thus distressed, and Aragorn, Frodo, and their little company eluded him.
He resumed the pursuit quickly, though, and found the Khaműl had been driven from the Last Bridge by his old enemy Glorfindel. The Witch-king, who only had one companion with him, was likewise unable to confront him openly. They regrouped and went south, rejoining with the other four. They managed to pick up the trail of the company of the Ring, and despite hindrance from Glorfindel and Aragorn managed to pursue Frodo alone on Asfaloth. The pursuit came to the Ford of Bruinen, and there Frodo compelled the horse to stop. The Witch-king saw his defiance and laughed, breaking his sword with a movement of his hand. But the waters of the Bruinen rose at Elrond's command, sweeping the Nine downstream.
The Witch-king took the only surviving horse back to Mordor, arriving there in December. He then sent aid to the other eight Nazgűl, and they returned in secret. In Minas Morgul they prepared for a grand invasion of Gondor at the order of their master. The Witch-king was given by Sauron added "demonic" force. On 10 March 3019, the signal was given and Minas Morgul was emptied. The Witch-king rode at the head of the army in black, upon a black horse, as he had in the time of the wars of Angmar. As the Witch-king passed out of the gates of the dead city, he sensed the presence of Frodo. He was disturbed, but continued on through Ithilien.
With the Witch-king in command, Osgiliath soon fell. The defeat was attributed to his superior numbers, and his terrible presence which made all hearts to quail. The Rammas Echor was breached, and the Pelennor Fields were overrun. Other wraiths he sent out mounted on Fell Beasts. Faramir, Steward Denethor II's son, was wounded by a dart and the black breath, but his company was saved by a sortie. Then the Witch-king laid siege to Minas Tirith itself, sending fire and the heads of the dead Gondorians into the city via catapults. Then he launched the assault.
He sent Grond out first, accompanying it in person so as to be the first to enter the city. Three times Grond struck the gate, empowered by the sorcery of the Witch-king. The third time the Gate shattered in a flash of fire. The Witch-king passed into Minas Tirith, but was confronted by Gandalf on Shadowfax. Gandalf forbade him entry, but the Witch-king laughed and put on a show of power.
The Black Rider flung back his hood, and behold! he had a kingly crown; and yet upon no head visible was it set. The red fires shone between it and the mantled shoulders vast and dark. From a mouth unseen there came a deadly laughter. 'Old fool!' he said. 'Old fool! This is my hour. Do you not know Death when you see it? Die now and curse in vain!' And with that he lifted high his sword and flames ran down the blade
As Gandalf stood resolute before the Witch-king, the Rohirrim arrived. Thus he departed, mounting a fell beast and descending upon King Théoden who led the attack. Snowmane, the King's horse, collapsed with a dart in the side, and Théoden was crushed beneath him. But the rider Dernhelm defied the Witch-king. The Witch-king threatened Dernhelm with a terrible death, but the rider revealed that she was a woman, Éowyn, and the Witch-king remembered the words of Glorfindel. He hesitated, but then moved forward. Éowyn decapitated the fell beast, but the Witch-king rose and struck her down with his mace, breaking her shield-arm. Then the hobbit Meriadoc Brandybuck stabbed him in the sinew of his leg with the blade of Westernesse (though there was much pain in his arm afterward) , as he drew back to kill the woman. Then Éowyn rose and drove her sword through where his invisible head was, and the sword broke as his crown toppled. The Witch-king gave a great and horrible wail, perishing at last.
So the prophecy of Glorfindel was fulfilled, for the Witch-king did not fall at the hands of a man, but at the hands of a woman and a hobbit. With his death, and the coming of Aragorn II in the black ships, the Battle of the Pelennor Fields was lost by Sauron.
Thanks to The Tolkien Gateway; http://tolkiengateway.net/wiki/Witch_King,http://tolkiengateway.net/wiki/Nazg%C3%BBl, Thanks to The Encyclopedia Of Arda; http://www.glyphweb.com/arda/b/blackriders.html, http://www.glyphweb.com/arda/n/nazgul.html, http://www.glyphweb.com/arda/l/lordofthenazgul.html,http://www.glyphweb.com/arda/w/witchking.html. Thanks to The Thain's Book (An encyclopedia of Middle-earth and Numenor)
