Governor-Militant Lukas Alexander
"Enemies of the Imperium, hear me. You have come here to die. The Immortal Emperor is with us and we are invincible. His soldiers will strike you down, his war machines will crush you under their treads, his mighty guns will bring the very sky crashing down upon you. You cannot win. The Emperor has given us his greatest weapon to wield. So make yourselves ready. We are The First Kronus Regiment, and today is our victory day!"
- – Governor-Millitant Lukas Alexander, making every xeno/heretic on the planet shit their collective pants
The Imperial Governor-Militant in Dark Crusade. Considered a step down in manliness from General Sturnn, Alexander is, in fact, his successor, and remains a fucking manly motherfucker, especially since Dark Crusade ends with a
canon partially canon ending for the Imperial Guard (since Alexander survives Kronus, only to die on Kaurava). So whilst he does not reach the manliness of the other Imperial generals in the series, he has the standard-issue set of fist-size steel balls all guardsmen have, and he is, as such, still pretty badass. He is notable for, like all the Imperial commanders in Dawn of War, showing considerable humanity, though he is younger and less-gritty than his fellows.
He has a noted role in Love Can Bloom.
The Dark Crusade
Alexander was dispatched with his unit of the Cadian 412th in order to bring Taldeer, who was largely responsible for the manly General Sturnn's
death near-death and the subsequent loss of a Dominatus-class War Titan. Having tracked her to Kronus, a planet under the rule of the Tau, Alexander commenced an orbital bombardment to clear out Tau observation garrisons before moving into the capital, reinforcing it and turning it into a formidable fortress with mazes of trenches, razor-wire, and minefields - the kind of battlefield the Tau loathe.
Shortly after landing, however, and his subsequent takeover of Ironworks Bay, the at-the-time General Alexander made a discovery with a contingent of Techpriests under his command - the main gun of an Imperator-class War Titan, cut from a Chaos Titan's arm ages ago. After Techpriests checked the cannon and found that the weapon had not been tainted by its use by the Traitor Legions (ironic since Chaos campaign outright stated that there was a Nurgle daemon residing in it [these are mutually exclusive, there is only a daemon in it if you are playing Chaos]), Alexander reported his findings and was given new orders: to take Kronus for the Imperium, and to salvage any relics of the Adeptus Mechanicus that may yet lie on this world. Massive support flew in, and Alexander's army swelled to gargantuan proportions, forming a spearhead that would eventually sweep all before it, doing his mentor, Sturnn, proud.
Things got complicated when Davian Thule's Blood Ravens unit arrived to purge the world and secure relics of their chapter (I.E. steal things and cover up inconvenient evidence of the Blood Ravens' hair-esy). Alexander had his orders from Segmentum Command, and wasn't about to back off because a few crimson-armored fuckwits refused to back off, despite pleading constantly that Thule was doing nothing but cause blood to be spilled needlessly.
Suffice to say Thule refused to fuck off. Canonically, the Blood Ravens drove the guard out of Victory Bay and off Kronus, but the wholesale slaughter that occurred was deemed heretical by several in the Inquisition and left several Blood Ravens with tortured consciences from the (largely needless) slaughter carried out - something that would eventually lead to the fall of Avitus, and which only later would be revealed to have been intended by the Blood Ravens' Chaos-tainted chapter-master, Kyras.
Despite his injuries, Imperial Medicaes patched Alexander up and got him off-world, where his reports to Segmentum Command caused the Blood Ravens to be flagged as possibly tainted by Chaos. Afterwards he (and his forces) were re-assigned to look into events of the Kauravan campaign - an unfortunate assignment that would, sadly, be Alexander's last.
The Death of the Governor-Militant
Shit hit the fan when the 1st Kronus Regiment was sent to assist the 252nd Kauravan in securing their system, which had recently been overrun with aliens and heretics. Unfortunately for the Liberators, problems arose immediately - Tau forces of the Fal'shia Sept had moved into the system and were reinforced heavily, putting up intense resistance. The men of the 1st Kronus Regiment suffered crippling casualties, including Colonel Bosch, whom the Governor-Militant had placed in forward command. Wondering what the hell was going on and why a bunch of aliens had just managed to waylay Alexander's forces, he moved in and proceeded to make a landing on one of the planets in the Kauravan system with a sizable contingent of his forces.
Shit went bad in a hurry. The 252nd Kauravan turned out to have huge numbers of their forces corrupted by Chaos - nearly 75%, forcing Alexander's forces to pick up the slack to assist Vance Stubbs in leading the loyalists against their chaos-tainted counterparts. After they were able to re-take a lot of the planet which housed the bulk of the 252nd's main base, Stubbs began to prepare for further operations, and Alexander moved his troops to act as a Vanguard, preparing to attack the Tau next, so as to establish a beachhead at a site with one of Kaurava's Ancient Gates.
Unfortunately, the Tau had been lying in wait. Not the forces Alexander was used to, Commander Or'es'Ka - a Tau Commander who rather infamously espoused the use of WMDs if it meant securing an objective - met the Imperials with overwhelming force - and barrages from the Ar'ka orbital cannon - grinding Alexander's troops down piecemeal. In spite of this, Alexander kept his cool, and directed his forces forward, inflicting enormous casualties on the alien space commies. Sadly, he then took a Plasma Rifle blast from Commander Or'es'Ka to the torso, burning a hole right through his chest (and armor), before the Sisters of Battle arrived. Angered over the loss of a loyal Imperial Guard unit who had truly gone above and beyond the call of duty, the Sisters of battle, after clearing out the location themselves, accused the 252nd of Heresy after noticing how the bulk of the 252nd, which Stubbs was the commander of, had gone to Chaos just before they arrived. Stubbs, of course, objected, swearing to drive Heresy and Xeno alike out of the Kauravan system. Empowered by righteous fury over the loss of a friend and ally in Alexander, Stubbs wept manly tears before proceeding to kick the shit out of every other faction in the Kauravan system in a fit of blind rage.
TL;DR: He dies in Dawn of War Soulstorm's intro, trying to help the 252nd Conservator Regiment (under Vance Motherfucking Stubbs) retake Kaurava. It sucks because it's a completely unceremonious death for someone who accomplished as much as he did. It's worth noting however, that the chain of Grit continued - Sturnn's near-death led to the rise of Alexander, whose death, in turn, led to the rise of Stubbs. To be fair, his death encouraged Stubbs to get his shit into the game, encouraging the 252nd Kauravan towards greater acts of bravery and valor, and eventually allowing Stubbs to
emerge triumphant in the Kaurava Crusade lose to Gorgutz as revealed in DoW III.