Being 175 years old, Captian Titus is considered relatively young compared to other Ultramarines and is 7ft 2in (2.18 m) and 750lb (340 kg). He has been is service to the Emperor as an Ultramarine for more than 150 years. During this small time in service, he has become a veteran of several major campaigns and gained a reputation as one of the mightiest Ultramarine captains.
Titus begins his life on the Agri-World of Tarentus in Ultramar. After being recruited by the Chapter, he passed initial training and became the best of his fellow recruits by excelling at every challenge. It was upon his first taste of combat as a Scout that Titus knew this was his place in life. Titus knew he was fighting a holy battle for the Imperium which caused his spirit to soar along with the fact that combat was as natural to him as breathing.
Titus’ natural ability of combat saved his life many times because he had yet to learn how to control his temper. Titus would continue to struggle with this throughout his youth. As years progressed, he would learn to control his temper, only losing it when something blocks his ability to do what he knows needs to be done. Off the battlefield, his aggression can be seen in fury of cutting words and plowing through opposition to take what he believes is the right course of action.
Titus gained much popularity and knowledge through his time on and off the battlefield. As a result, the esprit de corps amongst him and his battle brothers becomes stronger with each campaign. Having suffered the lost of many fellow Astartes, his relationship with his fellow surviving Marines has become ever important. After becoming Captain of 2nd Company, Titus feels it is his responsibility to make sure protect the Marines under his command. If one Marine is killed, Titus will do all that is necessary to make sure that debt is paid by the enemy’s blood.
In over 150 year’s service, Veteran Sergeant Sidonus has become the closest battle brother to Titus. Having become an Astartes several decades earlier, his relationship to Titus started out as a rookie-veteran. This would soon become a fast friendship. Sidonus had a “been there, done that, no problem” attitude that Titus would use as a sounding board for common sense.
Captain Titus is viewed as a “warrior who can do no wrong” mentor figure by Leandros, a young Ultramarine. Leandros is a proud Ultramarine; as a result he often quotes the Codex Astartes and will try to impress his commander by jumping into situations with fiery zeal. Captain Titus goes easy on the young Leandros because he too was a heady Astarte.
Unlike many Space Marines, Titus became interested with the philosophy behind his enemy’s attacks since his early tastes of combat. He wanted to know more about the enemy than just the big picture understanding of alien combat he learned in training. He sought to learn how enemy fought in small groups in the field. As he gained knowledge of the different combat styles of each alien species and daemon horde, he began to formulate battle tactics for each variety of enemies. Taking the time to learn how each enemy fought, he was able to learn their strengths and weaknesses and would take advantage of it in combat.
Captain Trajan, Titus’ former commander, respected Titus’ attempts to understand the opposition. This ability to anticipate the enemy’s plan of attack had saved many Space Marines through the years. Tragically, Captain Trajan was killed by Eldar in a routine mission that went horribly wrong. With Titus commanding the company, he hopes to become the leader that Trajan was.
Of all the enemies of Imperium, the creatures of Chaos number among the toughest for the Captain. Titus and his squad went up against a Chaos Sorcerer, who brought down the Ultramarines one by one leaving only Titus to avenge the fallen. Titus threw himself at the Sorcerer knowing that it meant his death. As the Sorcerer blasted him lighting bolts of Chaos energy, he stabbed his sword deep into the enemy’s chest. As Titus laid on the ground, he watched the Sorcerer take the last breath feeling only vengeance. Titus’ world turned into black in what should have been death. Somehow, to the confusion of the Apothecaries, he would survive his severe injuries.
Captain Titus is informed that his Ultramarines are the closest Space Marines to the Forge World Graia, which is under siege by the Orks. The planet is a valuable asset to the Imperium because it possesses valuable war machines known as Titans. Titus realizes upon arrival that the best plan is to attack the enemy first with a rapid strike using assault jump packs. Leandros tries to argue that it is against the Codex Astartes, but Titus ignores by urging the young Space Marine to keep up. Once on the Ork ship, Titus is unable to prevent the Ork Warboss Grimskull from escaping. He uses the big gun of the ship to blow it up and rides the ship as it crashes to the ground. Once on the ground, he meets up with Leandros and long time friend Chapter Sergeant Sidonus. As they make their way across the Ork-held territory, they link up with Lt. Mira, the only surviving Imperial Guard officer on Graia. She informs the group that Ork have captured a large gun emplacement and is currently preventing reinforcements from getting to the ground. Titus informs Mira to remain focus on strengthening the Imperial Guard outpost, as he and his Marines would take care of the gun.
On the way to the gun, the group is lead by Titus through enemy territory, killing all in their path. Once the gun is destroyed, the trio encounters a Servo-Skull trying to deliver a message. After it identifies Captain Titus, it plays a message made by Inquisitor Drogan informing them that the Ork is close to capturing highly valuable and deadly properties and should proceed to the Manufactorum to secure the safety of the Titan. After arriving at the Manufactorum, Captain Titus and his men seek out Drogan, who informs them that the Orks must not capture the power supply to a weapon of his creation. Titus leads the men through the factory searching for Drogan’s power source destroying all Ork in their way. Once they find it, Titus retrieves it only to have it explode due to its instability. Titus somehow survives the explosion and after traveling through sewers, he links up with Sidonus and Leandros and they continue on to meet up with Drogan. Inquisitor Drogan informs Titus that he shouldn’t be alive because the energy source can create a direct link to the Warp and the energies of Chaos. Despite the Inquisitor’s statement, the Space Marines move on, eventually meeting up with Lt. Mira and assist her in strengthening several crucial Imperial Guard locations.
Titus is informed by Drogan that the weapon he has created could wipe out the Orks, despite running the risk of destroying the planet. Captain Titus decides this is an acceptable risk and that they should proceed with firing the weapon. After Captain Titus fixes the issue of Orks cutting off the power of the weapon, Drogan fires the weapon at a planetary spire, which results in a direct link with the Chaos Warp.
As Titus and his Marines prepare for the final confrontation with Grimskull, scores of Chaos demons and Chaos Teminator sorcerer named Nemeroth emerge from the Warp. After subduing both the Ultramarines and the Warboss, Captain Titus can only look on as Inquisitor Drogan submits to the sorcerer. Nermeroth kills the Inquisitor and wonders why Titus has the ability to resist his dark powers. Nermeroth attempts to steal the power source for himself, but is interrupted by Grimskull because he claims he is more of a challenge to kill. As they fight, they fall over the railing into the abyss.
Unaware of the weapon's result, Titus comes up with the plan of destroying the Spire using the Imperial Titian at the Manufactorum. No one speaks against the plan, but Leandros becomes concern about Titus' connection to the Warp and it takes Sidonus silencing him for Leandros to put aside his concerns. As the Space Marines make their way back to the Manufactorum, they assist Lt. Mira and Imperial Guard in destroying whatever forces that appear in front of them. Upon reaching the factory, the Ork Warboss Grimskull challenges Captain Titus to one final battle, shouting that no "humie" could defeat him. After a fierce battle, Titus defeats the Warboss by blowing his head up into pieces.
Titus powers up the mighty Titan with Inquistor Drogan's mysterious power source and protects it while it is moved into position to launch a devastating attack on the Spire causing the Chaos Warp to close. Titus orders Leandros to call for extraction so Sidonus could take the power source to their ship so he could protect it until it could be delivered to the Chapter Command. As Sidonus prepares to leave, Nemeroth ambushes and kills Sidonus by impaling him with his claws.
Titus grieves with Lt. Mira and Leandros over the fallen Sidonus. Titus instructs Leandros to transform his grief into rage and direct it toward Chaos. Lt. Mira advises Titus to use his resistance to the Warp to complete his vow to kill Nemeroth before he ascends to a Daemon Prince. As Captain Titus begins his quest for vengeance, he is joined by the Blood Raven Chapter and his Ultramarine brothers, who had recently arrived. Having to use a combination of a Thunderhawk and assault jump packs, Titus fight his way to the top to confront Nemeroth. Nermeroth insists the Titus' connection to the Warp means he is destined to lead the Ultramarines in a fight against humanity. These claims are met by Titus' rebuttals that his destiny is the way of honor in destroying the traitors once and for all.
As Nemeroth emerges partially ascended, Titus assaults Nemeroth directly aided by his resistance to the Warp. Titus uses all his strength and fury to engage the Daemon Prince in direct combat as they hurtle towards the planet's surface. Captain Titus eventually kills Nemeroth by smashing his skull in.
Titus links up with his Space Marines, Lt. Mira, and Leandros after returning to the surface. As Lt. Mira assists Titus with his wounds, she realizes that Space Marines truly are human. Captain Titus can only respond "More than you know." They are interrupted by the arrival of members of the Black Templar Space Marine Chapter and Inquisitor Thrax.
Upon examining Titus, Inquisitor Thrax asks Leandros if he is sure of the charge of the captain "being corrupted by chaos." Leandros states that no "true" Space Marine could interact with a link to the Warp the way he had. Titus submits himself to the Inquisitor for investigation to prevent his Ultramarines and Lt. Mira from being dishonored and tortured. Captain Titus has one final conversation with Leandros, who defends his actions were of the Codex. Titus looks upon Leandros sadden saying that the Codex is a set of rules by which Marines should guide themselves by, but it is the manner in which you conduct yourself within the guidelines that truly make a Space Marine and by those standards Leandros had failed. Titus is last seen as he boards the Inquisitor's ship as prepares to leave the planet. As the text scrolls across the computer screen, it is mentioned that Captain Titus is order to a formal investigation of heresy by the Inquisitor Thrax.