Markus Corvinus is the first vampire in the Underworld storyline, portrayed by Tony Curran. He is the son of the first immortal and was bitten by a bat, thus making him into a Vampire.
Markus was one of three sons of Helena and Alexander Corvinus. He, along with his twin brother, William, inherited the same virus which transformed his father into the first true immortal. Markus had a strong bond with William. While William was bitten by a wolf which resulted in him becoming the first Lycan, or werewolf, Markus was bitten by a bat which transformed him into the first Vampire.
William went on to ravage the countryside of Hungary, infecting the populace with his highly infectious lycanthropy virus. In order to combat the growing Lycan threat, Markus approached Viktor, a dying warlord, to borrow his military genius and army (who became the Death Dealers) in exchange for immortality. Viktor accepted and became one of the Vampire Elders. Markus also personally infected Amelia, making her the first Vampiress Elder.
In 1202, Viktor led a charge into a Hungarian village which William supposedly passed through. Instead of finding only William, they found an entire village of Lycans. Death Dealers, including Amelia, subdued and injured William before Markus, who pleaded for his brother's life before Viktor. Viktor, thinking that if any of the Corvinus brothers were killed the immortal bloodline would eventually die, locked William far away from the reach of Markus. Markus, then swore vengeance against Viktor and all those loyal to him, but was able to do little, as the Death Dealers were loyal to Viktor alone.
After William was captured, the "Chain" was constructed, a system when only one Elder ruled while the other two slumbered. Supposedly, Markus ruled the two covens (the New World and Old World), but power was truly in the hands of Viktor, the ruler of the Old World coven. Viktor started to gather more power to himself to become the true leader of the Vampires, going as far as to alter history into naming him as the original Vampire. Later, Markus supposedly frowned upon the practice of feeding on humans. Markus claimed that he enjoyed the company of Andreas Tanis, the Official Historian of the Coven, most likely because Tanis knew that Markus was indeed the original vampire. However, Viktor and Amelia undercut Markus' power, ensuring he would never have the strength to free his brother.
Much later, on the eve on Markus' awakening for his century of rule, a Lycan plot, led by the presumed dead Lucian, to combine the bloodlines became evident. A captured Lycan scientist called Singe explained Lucian's plan under dress and was killed by a death blow from Viktor. His blood seeped into Markus' tomb and revived the slumbering Elder, turning him into a Vampire-dominate Hybrid, with claws, bat-like ears and bladed wings. He beheaded the treacherous Kraven (who had attempted to assassinate him) with his wing-spikes, not before learning the regent's memories, and burned down Ordoghaz, the Old World Coven. Determined that the time has come to free William, he sought to find Selene, who held half of the key to William's dungeon. He failed on his first attempt thanks to Michael Corvin, his distant relative who was a Hybrid. He learned from Tanis, that the other half was held by his father, who had retrieved it from Viktor's body. Attacking again, he seemingly killed Michael, and drank Selene's blood, learning the location of his brother. Markus then confronted his father, and revealed his true plan - to rule over a race of Hybrids. Markus then mortally wounded his father, and retrieved the other half of the key.
Journeying to the old fortress, Markus then released William from his dungeon. Their bond was so strong, that even the crazed William refused to harm his brother. They were soon interrupted by Selene and the survivors of his father's company. Markus combated Selene and was enraged when a resurrected Michael killed William. Markus drove a wing-spike through Selene, who survived due to her drinking of Corvinus' blood. However, Markus was distracted by the death of his twin, and wracked by shock and disbelief. These emotions caused him to be temporarily stunned & off guard and gave Selene her opportunity. She broke off the spike and impaled Markus' head with it before shoving him backwards into the still whirling blades of a crashed helicopter, killing him.
The prequel novel to the original Underworld, "Blood Enemy", revealed Markus had a son called Nikolas, who was due to be wed to Viktor's daughter, Sonja, who believed that Nikolas was the only suitable consort for his daughter due to him being the son of an Elder. However, Nikolas was a grave disappointment to Markus, preferring brief affairs with the mortal servant girls to a long-term relationship. After Sonja's death at Viktor's hands and Lucian's subsequent escape, Nikolas tracked down Lucian and engaged him in combat, only to be killed when the Lycan learned how to transform into his wolf form without the aid of the full moon. It is unknown how this affected Markus.