Under the Azeroth Allied Forces' naval offensive, every region except Talador, the Army of the Light's heartland, had fallen.
Gorgrond, Frostfire Ridge, Nagrand, the Spires of Arak, and even Shadowmoon Valley—due to the defection of the Draenei archbishop Akama, the Draenei of Shadowmoon Valley withdrew from the Army of the Light.
The massive coalition formed to defeat the Army of the Light broke through from every region of Draenor and ultimately converged on Talador. Here, the coalition would fight the Army of the Light to the finish.
Without the Light Dissolution Domain, the Army of the Light's many Naaru simply hung directly in the skies over Talador, continuously using their power to grant all manner of buffs to the Lightbound and Lightforged, while occasionally firing beams of Holy Light energy at the coalition below.
This siege of Talador was launched simultaneously. Forces from Draenor's other two regions attacked the Army of the Light in Talador with utmost ferocity, while large battlefield glyphs forged from the power of Azeroth's guardians were also deployed.
With the enhancement of those large battlefield glyphs imbued with the guardians' power, and with all sorts of buffs piled on, the coalition's warriors no longer held even the slightest disadvantage against the Army of the Light's Lightbound and Lightforged, who were bolstered by countless Naaru.
After an incomparably bloody and prolonged battle, the Army of the Light's Lightbound and Lightforged suffered grievous losses. The coalition even used various methods to kill more than a dozen Naaru. The great Naaru A'dal ordered the Army of the Light to retreat and make its final stand in the fortress city of Shattrath.
As the great Naaru A'dal's headquarters, cultivated over countless years, Shattrath possessed an extraordinarily powerful Holy Light energy barrier. That was why Shattrath had withstood the fierce assaults