Verghast is an Imperial Hive World in the Sabbat Worlds Sector that became a crucial point of contention in the Sabbat Worlds Crusade in 761.M41 when Chaos corrupted the people of the hive city of Ferrozoica and these Chaos Cultists, numbering some 13,000,000 people, almost the entire population of the hive, in turn attacked their old rivals, the nearby loyal hive cities of Vannick and Vervunhive.
Vervunhive, despite having a larger population, could field military forces numbering only about 500,000 troops to meet the Zoican forces, so its leaders sent out an astropathic plea to the Imperial Guard for forces to defend itself and to the Northern Collective hive cities of Verghast for Planetary Defence Forces (PDF) to hold the line against the vicious horde of Zoican Chaos Cultists, heavy armour and mutants. During the resulting battle, Vervunhive was all but destroyed by the Forces of Chaos' assault. The hive city was essentially abandoned in the wake of the attacks.
The citizens of Vervunhive found refuge in the hive cities of the Northern Collective, established new, smaller settlements in the region where Vervunhive once stood or joined the regiments of the Imperial Guard engaged in the Crusade to retake the Sabbat Worlds Sector. Many former Vervunhive citizens who had defended the city as part of its irregular Scratch Companies later joined the famed Tanith First and Only Regiment of the Imperial Guard which had participated in the defense of the city as part of the Act of Consolation declared by Warmaster Macaroth of the Sabbat Worlds Crusade, which allowed civilians to join Imperial Guard Regiments if they wished without going through the normal recruitment process.
Battle of Vervunhive
After receiving Vervunhive's request for assistance in facing the Zoican assault, the Imperial Crusade in the Sabbat Worlds Sector dispatched the Tanith First and Only Regiment of the Imperial Guard to aid the hive city's defense, as it was not known at the time that the Zoican forces were servants of the Ruinous Powers. The Tanith First and Only took up defensive positions on the southern side of the hive, manning the walls alongside the Vervunhive Scratch Companies and paying particular attention to the city's main access points, including the Veyveyr Rail Gate and a heavily-polluted area outside the city's defensive walls called the Spoil.
Early in the deployment, the Tanith Regiment witnessed the massive explosive flashes of the thermonuclear detonations that the Zoicans unleashed against Vannick hive, which reduced the massive hive city to a radioactive scrap pile. Vervunhive was protected from artillery bombardment by a powerful void shield which was projected over the top of the hive, but the garrison was under constant assault by Zoican soldiers in heavy infantry armour and a powerful force of Zoican main battle tanks. However, the corrupted High Master Salvadore Sondar of Vervunhive, following orders from the Chaos Warlord, the Heritor Asphodel, who was the commander of the Zoican forces, deliberately lowered the void shield at a crucial moment to allow the Zoicans to unleash a full bombardment.
Much of the hive city was destroyed in the devastating barrage until a desperate strike force led by Colonel-Commissar Ibram Gaunt, the commander of the Tanith First and Only, managed to infiltrate the High Master's quarters and bring the void shield back online. Gaunt then led another strike force composed of the Vervunhive irregular Scratch Companies, the Tanith First and Only and the troops of the Volpone Bluebloods into the massive armoured assault crawler that served as the Heritor Asphodel's mobile headquarters and destroyed it, after Colonel-Commissar Gaunt engaged and killed the Chaos Warlord in single combat. With their leader dead, the Zoican forces soon became disoriented and their assault was turned back.
Shortly after this victory, Warmaster Macaroth, the Lord Commander leading the Sabbat Worlds Crusade, ordered massive reinforcements to be sent to the planet once the Imperial Guard forces there reported the sheer strength of the Forces of Chaos present there. The new forces sent to Verghast included 6,000,000 Imperial Guardsmen, 500,000 main battle tanks, 3 companies from both the Iron Snakes and Imperial Fists Space Marine Chapters and 2 Titan Legions. This overwhelming show of Imperial force proved adequate to exterminating every last remaining Zoican cultist on the planet and Verghast was declared free of Chaotic taint.
The Warmaster next issued an edict known as the Act of Consolation which provided Imperial support for the construction of new hive cities to replace Vanickhive and the ruins of Vervunhive which also allowed the civilians of Verghast to join Imperial Guard Regiments without going through the standard tithing process if they desired. Many of the survivors of Vervunhive who had served in the Scratch Companies alongside the Tanith First and Only willingly joined that regiment.
- Necropolis (Novel) by Dan Abnett