Icecrown Citadel

Icecrown Citadel is the greatest fortress of the Scourge and the last bastion of the dread Lich King. Located in the frozen wastes of Icecrown on the continent of Northrend, the Citadel is built around the Frozen Throne that once held the spirit of Ner'zhul until he joined with Arthas Menethil to become the new Lich King. Constructed from saronite, the Citadel is inhabited by some of the strongest and vilest of the Lich King's minions - a great army of the living dead standing between their dark master and those who seek to destroy him.

History
When Kil'jaeden hurled the Lich King into the mortal world, Ner'zhul's prison of ice, known as the Frozen Throne, slammed into the icy spire of Icecrown Glacier. As the Lich King expanded his influence, the Scourge and the dreadlords built Icecrown Citadel. Arthas Menethil and Illidan Stormrage wrestled for the control of the citadel. As Illidan was defeated, Arthas shattered Ner'zhul's prison and merged with the Lich King. Death knights like Thassarian and Koltira Deathweaver were here, training until the Lich King awoke and commanded his subjects to invade the Light's Hope Chapel.

At the start of the war against the Lich King, Trag Highmountain defended Taunka'le Village in Borean Tundra from an Anub'ar attack. The undead tauren fell into their tunnels and continued through them, emerging in Icecrown, with the Icecrown Citadel looming above him. Fighting his way through the Scourge, he soon entered it and clashed with the Lich King. As he was trying to control him, the Lich King blasted Trag out of the citadel.

Wrath of the Lich King


''Icecrown Citadel dominates Northrend - visible from farther away than nearly any other structure and home to the greatest army of undead in the known world. Inside dwells the Lich King - a tyrant with nearly godlike power over his tireless, seemingly infinite subjects - and the will to bring Azeroth to its knees.''

''An assault on the mighty citadel is among the most dangerous undertakings in the history of Azeroth - and the most pivotal. The legendary heroes Highlord Tirion Fordring of the Argent Crusade and Highlord Darion Mograine have joined forces to lead the charge through Icecrown's fortified gates, and both the Horde and Alliance have sacrificed lives - indeed, whole battalions - to get this far. They dare not fail. The Lich King's reign must end.''

Icecrown Citadel is a massive structure located on the Dragonblight-Icecrown border. Its southern entrance, Angrathar the Wrathgate, is surrounded by the Court of Skulls, and flanked by Fordragon Hold and Kor'kron Vanguard. The fortified northern entrance to Icecrown Citadel, surrounded by the Court of Bones, is found in the mountains of southern Icecrown. It is surrounded by gigantic ramparts and massive, blade-like spires, the towers are an imposing landmark of the Icecrown skyline, emitting a beacon of light from its pinnacle.

Icecrown Citadel is home to the final encounter in Wrath of the Lich King, featuring the Lich King as the final boss. Although players interact with Arthas numerous times during the expansion, including during an event at Angrathar the Wrathgate in the Dragonblight, the instance where the final battle against him will take place was not formally announced until nearly a year after the release of the expansion. The developers have stated that they feel it was a mistake to release Black Temple, wherein the Illidan encounter takes place, as soon as they did (a mere four months after the release of Burning Crusade). Their goal for Wrath of the Lich King was to ensure that Arthas did not become just another farm boss too soon before newer, more challenging content is released.

Icecrown Citadel received an exterior redesign in patch 3.3.0, with the opening of the raid instance inside; the central spire became much taller and more cylindrical, and a platform of ice was added at the spire's summit (where the Frozen Throne will be inside the instance).

Legion
Several adventurers entered the halls of Icecrown in search of mighty weapons to fight the Burning Legion with.

Shadowlands


After the defeat of the Lich King at Sylvanas Windrunner's hands, as announced by King Terenas years earlier, the now-masterless Scourge will be marauding all across Azeroth. Off the heels of yet another brutal war, the forces of Azeroth will have to mount a counterattack and assault the source at the Icecrown Citadel.

In the RPG
From the name, one would assume Icecrown Citadel was an enormous fortress planted on the glacier, with thick walls, sturdy guard towers, and massive front gates. Not quite. Most of the Citadel lurks below the surface. The glacier is split, creating a deep fissure. Scourge forces lurk down there, and they have carved levels into either side of that massive split and created bridges, walkways and even solid floors across the gap. Not surprisingly, Icecrown Citadel is a cold, unforgiving place. It has no decorations, no furs or rugs, no fires, nothing to provide comfort or warmth. The Scourge creatures move silently from one problem to another, focused on their tasks. All manner of undead dwell here, including zombies, wraiths and beings composed of cold energy. At the bottom of the rift is the Frozen Throne, the heart of the Scourge and the Lich King's personal seat. This throne is the remains of the block of ice that first brought Ner'zhul to Azeroth, the same block that held him prisoner until Arthas freed the ancient orc shaman and merged with him. Arthas sits on the Frozen Throne.

Notes and trivia

 * A majority of sources, including the Warcraft III game manual and, state that the Citadel was built around the spire long before Arthas and Ner'zhul merged together. However, the Warcraft III: The Frozen Throne finale cinematic depicted the icy spire of Icecrown as naked under a dome of ice with no other structure around it except a gate (and possibly the walled obelisk plaza). Road to Damnation describes the Citadel's spire differently than what is seen in the game; with a path from the citadel downward through a series of halls and rooms, eventually reaching a huge cavern deep beneath the earth. In the center was the spire with the Frozen Throne. Also, the official Shadowmourne preview blog post stated that it was constructed after by stating that Frostmourne's likeness has even found its way into the architecture of Icecrown Citadel. Then the Ultimate Visual Guide and its updated version too stated that the Citadel was constructed after Arthas became the Lich King.
 * It is possible that there were two Citadels, one underground made of ice and one above ground made of Saronite. With this view, the main contradiction is the depiction seen in "Fate", which shows it already the modern version.
 * Torghast is the source of inspiration for the architecture of Icecrown Citadel.
 * The in-game architecture of Icecrown Citadel and the outlying Scourge fortresses bears a striking resemblances to artwork of Orthanc, Barad-dûr, and countless other dark citadels from The Lord of the Rings.
 * In Hearthstone, the Icecrown card back was rewarded for achieving Rank 20 in Ranked Season 5, which took place during August 2014. The flavor text reads: "In the frozen heart of Icecrown Citadel, a hero's mettle will be tested. Bring a parka."