Del'Khan Campaign

The Del'Khan Campaign was an imperial military campaign to liberate the besieged Industrial World of Del'Khan in Segmentum Pacificus from a foul, warp tainted Xenos race. When the PDF and Imperial Guard Regiments on the planet send out a request for reinforcements, a Liberation Fleet was quickly assembled but even these forces proved nearly hopeless against the Xenos onslaught. Now a call for the Emperor's angels of death was sent. Elements of more than five Space marine chapters, including the entirety of the 2nd and 5th companies of the Hunters Chapter as well as the 3rd, 4th and 6th companies of the Slayers Chapter. While the Del'Khan Campaign ultimately ended in Imperial victory it was revealed that this war had only just begun as suddenly a wave of desperate calls for help rung out from across the sector, having been attacked by similar aliens. This initiated the Amontis Crusade which aimed to eradicate this hostile xenos being from the face of the galaxy while they could still be contained. 
==Prelude==
How the planet was infected by these odd and completely mysterious and semi-sentient half-warp Xenos was not know at the start of the invasion. No ships of alien design had been spotted in the system in centuries. The attack was sudden, random and ruthless, with the foul Xenos beings seemingly appearing out of the shadows. Violent distortions in the planets magnetic field, as well as disturbances in other sensor equipment, seems to be the only logical clue to when the first wave of these Xenos arrived on the planet. Del'Khan would, throughout the entire Campaign, continue to experience these disturbances, greatly hindering Imperial communication and surveillance across the planet.
The first signs of the Xenos on Del'Khan was sightings of odd beings quickly moving through the highlands on the planet's eastern continent. A patrol was dispatched to investigate but was never heard from again. This prompted the PDF to send a larger and more well-equipped search party into the highlands to find the missing patrol. The search party, counting around a full platoon, looked for days without any luck. It was at the 12th day that some of the soldiers discovered that the environment was beginning to change. The densely forested highlands seemed to suddenly wither and die with the earth seemingly turning hot and burned. Only a few hours after the search party had headed deeper into this dying area did they discover the burned and brutalized remains of the patrol. The discovery was reported back to command but before the platoon could carry on with their search was it suddenly assaulted by strange beings. The platoon commander quickly saw that these things weren't native to the planet and realized that it somehow was a Xenos force of unknown origin. The Xenos creatures charged the PDF troops with speed and their sharp teeth and claws easily tore through their armor. The platoon's vox operator managed to send out a final warning before he and the rest of the troops were slaughtered.
===Amadan Long Beach Massacre===
The planetary governor, facing a potential scout force of unknown Xenos on his planet, decided to deal with these aliens that had suddenly appeared with his own forces. He gathered up a large army of troops and prepared them to be deployed on the Amadan Long Beach where a forward base would be constructed for the troops to operate from. Unfortunately, the governor had horribly underestimated just how far the aliens had spread throughout the Highlands. The Imperial force that first set foot on the beach to construct the base was assaulted within the first two hours. The base and all personnel were lost in this assault. This failure greatly angered the Governor who then ordered his army to immediately launch their attack on the beach. The odd magnetic and electronic disturbances had made it hard for the orbital platforms to scan the areas around the planet, particularly the Highlands, but after weeks of trying to calibrate the sensors it finally succeeded to bypass the interference and get a clear view of the activities down on the planet. What the orbital platforms observed frightened them all and they quickly tried to warn the Governor and begged him to call off the attack but it was too late as the assault could no longer be aborted. Early in the morning of 39,231 M42 made more than a million Del'Khan PDF troopers landfall on the Amadan Long Beach. The human soldiers were met with a wall of Warp fire being launched from the beach up at their Valkyries and other airborn troop transports. Thousands died in the opening minutes alone and those who survived to get down on the wet sand was meet with more Warp fire, claws and teeth as the aliens charged at them with untamed demonic ferocity. The aliens had gathered in large numbers near the Amadan Long Beach for purposes later known for being constructing a sort of underground hive.
The Imperial attack continued for another three hours but eventually was the Imperial command forced to see that the situation was hopeless and called for the remaining forces to withdraw. While the commander managed to save around 200,000 troops, he also abandoned around 5,000 souls that were now trapped on the beach without any means to escape and left to be slaughtered by the aliens. A last vox transmission from the trap troops was from one sergeant Calvus Grather who had taken command of the trapped troops. In the transmission, he proudly proclaimed that they would fight to the last man in the name of the Emperor and take as many of these foul Xenos beings with them as possible. After the conclusion of the one-sided battle, the Imperials began to refer to these Xenos as the Amadan Xenos, naming them after the now bloody beach where the Imperials first truly battled them.
===First battle of Tas'Nook City===
The Massacre at Amadan Long Beach took a great toll on the planet's moral. The commander that had been in charge of the attack on the beach was executed for incompetence and a new commander was appointed to take his place. While the planet's nobility fought among themselves about what cause of actions to take next, the Amadans completed the first stage of their hive and then began to spread outwards to claim more land and create more hives. With the first hive finished, the number of Amadan on the planet drastically increased and soon smaller settlements were being attacked or wipe out. The PDF took a defensive stance to try and contain and counter the Amadans movements but without success. Within the first month had the first hive, now called the Central Hive, advanced to stage tree while four other hives had been established beyond the Highlands. It was when the central hive achieved stage three status that the Imperials discovered that the Amadans now had access to a wide teleportation network that had a radius of more than 2,000 kilometers with its center being the central hive. This teleportation would take the form of burning warp meteors, carrying 5-15 Amadans depending on the size of the pod, dropping from small warp portals that would appear in the stratosphere.
The city of Tas'Nook, a key industrial site on Del'Khan, was located within this radius and came under siege only a few weeks after the Imperials had documented that the central hive had reached stage three. While the Imperials had worried about the defense of the city and its industrial zones, the Amadans had, during the weeks up to the impending siege, been razing smaller towns and industrial zones. These minor attacks put a strain on the Imperial PDF troops as they were being stretched thine to try and protect as many settlements as possible.
The siege began with a massive force of tens of thousands of Amadans charging the walls of the city in the middle of the night followed by warp fire artillery from further outside the city limits. The bombardment of these warp fireballs threw the Imperial citizens and soldiers into chaos and disarray. While the Amadans ability to use what equaled to warp based artillery, as seen during the Massacre at Amadan Long Beach, this was on a whole other scale. Large projectiles of Warp fire rained down into the streets and set the factories and refineries aflame. While the walls managed to hold the tide of charging Amadans at bay for some time, it was still getting hammered from the warp fire that smashed through the Imperial fortifications. A crack in the Imperials defenses was eventually formed and the Amadans took full advantage of this weakness and swarmed into the city, killing everything in sight.
While the Amadans managed to break through Tas'Nook's outer walls on the first day. the battle would still drag on for another week as Imperial reinforcements arriving from the Cyel Work Zone. Del'Khan's governor refused to let Tas'Nook City fall, as it was the second largest industrial zone on Del'Khan. This refusal to abandon Tas'Nook led to many PDF troops stationed on the eastern continent being redeployed to Tas'Nook to try and secure the city and the surrounding region.