Argel Tal was the Captain of the 7th Assault Company of the Serrated Sun Chapter of the Word Bearers Space Marine Legion during at least the latter half of the Great Crusade. Later, he would be referred to as the Crimson Lord of the Gal Vorbak; captain of the Word Bearers' first daemon-possessed Space Marines.
Tal was a native of Colchis, inducted in the Word Bearers Space Marine Legion by First Chaplain Erebus, who at first had chosen him to become one of the Legion's Chaplains. But eventually Argel Tal took up the role of Captain of the 7th Assault Company in the Serrated Sun Chapter. Being onboard the light cruiser Orfeo's Lament alongside Ingethel the Ascended, Argel Tal witnessed the horrible world beyond the Eye of Terror, while undertaking The Pilgrimage ordained by Primarch Lorgar. While in The Eye, he was bonded, unknowingly at first, with the daemon Raum. He returned to the Legion, and after Lorgar's request he divulged to the Primarch his experience in the Immaterium, providing useful insight for the Book of Lorgar. In honor of his achievements in the Chapter, his Primarch installed him as the Captain of his Gal Vorbak (the "Blessed Sons") an elite cadre of warriors who were the first to wear the crimson colour on their power armour. Leading the Gal Vorbak, Argel Tal descended finally on Isstvan V against the Raven Guard and their loyalist allies, the Salamanders and the Iron Hands.1
It was shown to Lorgar by Ingethel the Ascended during his sojourn into the Eye of Terror that Argel Tal will become much more powerful, becoming taller than a Primarch in his Daemon form, and will fight and die during the Siege of Terra. He is said to be killed by the Primarch Sanguinius after rampaging through a squad of Imperial Fists.2a However Erebus would later claim that this was only a potential future.
After Istvaan V Argel Tal gathered together survivors of broken Word Bearer companies and formed the Vakrah Jal, the Chapter of Consecrated Iron, a new elite unit of Possessed Marines that would train in the fighting pits of the World Eaters aboard their flagship Conqueror. He later fought in the Shadow Crusade alongside World Eaters 8th Captain Khârn, whom he had become friends with during the course of the Great Crusade and Horus Heresy. He took part in the Battle of Armatura and the Nuceria Massacre and in the latter was murdered by Erebus, as Erebus claimed Argel Tal's influence would prevent Khârn from embracing the Ruinous Powers and thus cost them the war3a. Ingethel's prophecy that he would "die in the shadow of great wings" was fulfilled as he died in the shadow of an Aquila on top of the Imperator Titan Corinthian.3