Although considered relatively young by the standards of the Astartes, he is already a decorated veteran of several major campaigns waged across the galaxy by his Chapter.
His exploits have earned him a reputation as one of the greatest heroes of the Ultramarines, despite his relative youth.
Over the course of his long service, Titus has overcome countless opponents and suffered many wounds, both physical and psychological. In his early days as an Astartes, he struggled to overcome his own temper.
Later, he survived the death of his entire squad at the hands of a Chaos Sorcerer; Titus killed this corrupted servant of the Ruinous Powers, but suffered grievous wounds in the course of the battle -- and some in the Chapter have questioned how he survived, intimating that he himself may have been touched by the corruption of Chaos.
Titus became the Ultramarines 2nd Company's commander when his former captain died in battle. He was by his mentor's side when he fell, and still feels the weight of taking over his mantle of command.
Titus faced his greatest test when he and his company of Ultramarines were sent to the Adeptus Mechanicus Forge World of Graia in the Segmentum Tempestus to stop an invasion by an Ork WAAAGH! 1 million Greenskins strong led by the Warboss Grimskull. Grimskull was intent on stealing advanced Imperial weapons, including a Warlord-class Battle Titan.
The assault was part of an intricate plan unleashed by the Chaos Sorcerer Nemeroth, the Chaos Lord of a warband of Chaos Space Marines known as the Chosen of Nemeroth, to get his hands on an experimental power source on the world that would allow him to ascend to become a Daemon Prince. Accompanied by 2 members of his command squad, Sergeant Sidonus and Battle-Brother Leandros, Titus joined with the Imperial Guard's 203rd Cadian Shock Troops Regiment and its only surviving officer, 2nd Lieutenant Mira, to eventually kill Grimskull and halt the WAAAGH!
Unfortunately, the Ordo Xenos Inquisitor Drogan, who Titus and his Astartes relied upon for assistance in retaking the world, was actually an undead pawn of Nemeroth who used a specially designed weapon powered by the experimental power source Nemeroth wanted, to open a portal into the Warp that allowed the Chaos Sorcerer, a horde of Chaos daemons and his Chaos Space Marines to come to Graia.
Curiously, however, Titus displayed an unknown immunity to the sorcerer's psychic powers which immediately raised the suspicions of the highly orthodox Leandros to his commander's possible corruption.
Following the death of his old friend Sidonus at Nemeroth's hand, Titus hunted down the foul Chaos Sorcerer and slew him just as he was in the throes of the ascent to daemonhood, banishing his dark soul back to the Warp for punishment by his Dark Gods.
Unfortunately, after saving Graia, Captain Titus was taken into custody by the Inquisition's Inquisitor Thrax and his retinue of Black Templars Space Marines on suspicion of heresy after Leandros reported his captain for both his resistance to Nemeroth's sorcery and his multiple deviations from the Codex Astartes held sacrosanct by all Ultramarines. His current fate is unknown.
Titus was an unusual Ultramarine who believed that the Codex Astartes offered an excellent series of guidelines for what it meant to be an Astartes, but that it was not sacred writ to be followed soulessly and automatically.
He believed that the spirit of the Codex was more important than its letter and that how one chose to live out the directives contained within it truly determined if one was an Astartes or not.
Titus has displayed a potent resistance to the psychic powers unleashed by the servants of Chaos on multiple occasions, the origin of which is unknown but which has laid suspicion upon him of somehow having been corrupted by the Ruinous Powers.
There is no sign of such a taint, nor has the captain been deemed to be a psyker, so the nature and scope of this resistance remains unknown at the present time, though this ability led to Titus' arrest after the campaign on Graia by the Inquisition.
It is presumed he is currently undergoing a rigorous interrogation and tests of purity at Inquisitor Thrax's hands.
Perhaps the captain's most distinctive piece of equipment was a weapon that fired explosive mines that generated a gravitic field and would stick to foes before exploding, which was called the "Venegance Launcher."
At the time of its release, the developer of the Space Marine video game claimed on its forums that it took place in a parallel Warhammer 40,000 universe where the Ultramarines 2nd Company is commanded by Captain Titus rather than Cato Sicarius.