A century ago, the Trident Sector on the North Eastern Fringes of the Imperium erupted into war as Eldar forces declared war in an attempt to rescue artifacts that were locked in Imperial museum vaults. They almost succeeded were it not for the intervention of Chaos troops whom captured the artifacts from the very jaws of the Eldar. The Blood Angels were called to form the core of Imperial defence's within the sector and they were called into action again as Eldar forces again battled across the planets of the Trident sector against Chaos forces that not only captured vast ground, but forced a stream of refugees away from the sector, hampering its production of such a resource rich sector. The Blood Angels were pushed out by growing Ork incursions, attracted by the escalating war. The subsequent lull followed two decades of Chaos control before the previous population centre's 'Lesser Trident' were sealed off by the retreating Imperium. Meanwhile the Imperial port colony, Isaac was captured by Eldar troops attempting to halt Imperial experiments on a specimen they were holding in containment, Imperial forces stormed the beaches in an attempt to wrestle control back from he defending Eldar forces. The subsequent disruption allowed for the release of Necron forces that had been lain dormant in the Trident Sector. The original artifacts the Eldar had been searching for had been used by the Imperium to unwittingly unleash an ancient C'TAN, and their subsequent ravaging of the sector resulted in a huge dead zone of space that no ships dare enter, and the borders of which are patrolled by Chaos forces. The Imperium still held some colonies on the Greater Trident Sector however soon the planet of Aridia became a flash point triggered by separatist movements, taking advantage of the trade route disruption caused by the appearance of the Necron dead zone. The Ultramarines were deployed as they came under attack from two major uprisings, one triggered by a Tyranid cult in the first Tyranid sighting within the Trident Sector and the other by Chaos Night Lord forces looking to expand their own operations into the wider sector. Aridia became a grim world inhabited by bands of forgotten Tyranids and Orks and a stranded company of Astartes form the SubTerra chapter. The Night Lord forces sealed the city of Arnor, entrance in or out was by space port only. The Tyranid sighting was of the gravest concern for the Imperium however, but before warnings could reach the remaining colonies the planet of Auriantia would come under attack and subsequently be destroyed, despite stiff resistance from the Guardsmen of Outpost MXII who may have at least bought some time for the evacuation. Faced with a once affluent sector that supplied many precious resources the Imperium had lost everything with Night Lords Chaos Space Marines commanding much of the vital former colonies. The sector was also now a gateway threat to the Imperium from Tyranid and Necron attacks and also contained unchecked spawning grounds for Orks. The sector remained of much scholarly interest however and the continued knowledge of an Eldar presence there, indicated that there were many ancient secrets of the universe lying unfound there. The most significant battle of Trident came at Emperor's reach, the gate to the sector from Imperial Space, and as geared the Orks and Tyranids soon found it. It was here that the Adeptus Sororitas began the Imperial fight back, pushing back the Tyranids and gaining controlling of the sector fringe, before the crowning achievement of foiling an attempt by the Night Lords to capture the warp gates. Following this, patrols located an ancient Eldar Webway Gate, and despite encountering Eldar, Ork and Chaos forces, the Imperial forces of the White Scar and Ultramarines Space Marines captured the gate, opening up untold if dangerous transport opportunities.

And so we come back to Trident, a century after the turmoil began, and migrants, some sanctioned many not are flooding into the sector, enchanted by the promises of a 'new frontier', of lost treasures and new promises, despite the many hidden dangers awaiting. Deployed at the gate and in the small sector of control the Imperium has are representatives of three Space Marine Chapters, and there are rumors of a mysterious force of black deathly marines escorting and saving lost bands of migrants. The increased Imperial activity has caught the attention of the Night Lords marines who are looking to create a buffer between themselves and the Tyranids now present in the South East of the greater sector. The numerous Orks of Trident are also being stirred up by settlers re-occupying lost cities only to find them the improvised homes of greenskins. All the while the Eldar watch on, waiting for a chance to shut-down the gate.

Post tournament plot: With the warp gate open, both illegal and illegitimate transport flooded into Trident, the chance to re-pioneer a rich and vast system being too great a lure. Despite Imperial warnings and threats settlements soon began, although many found themselves immediately under the levy of the Ministorum that had now opened traffic into the sector. Eldar forces that had been hiding in watch were exposed and eliminated by the Ultramarines as they pushed out their borders. The Blood Angels however had a much tougher time, having to expend large amounts of firepower and resources battling back rampant Tyranids and greenskins. It was then that they were set upon by the Night Lords who came near close to causing critical damage to the Blood Angels. However before the Night Lords could complete their work, and remove the Imperial protectors from the new settlements, a mysterious company of Marines descended upon them, pushing the Night Lords back into retreat, before promptly vanishing as the Ultramarines moved in to attempt to cut off their retreat. Slowly but surely, Imperial forces were back in Trident, and already it was providing both resources and living space that outstripped the cost of deploying Space Marines and training Planetary Defence Forces.

Meldtown 3: The Ultramarines had deployed the largest amount of forces to the Trident sector, although they had had a history there as long as the Blood Angels they had set it upon themselves to make them the primary protectors of the Imperial push. One such attempt came at capturing a tillium rich planet for a mining colony that was relatively isolated and would require minimal future defence. Engaged by Chaos And Eldar forces alike the Ultramarines failed in their objective, as the Eldar forces that had lost so much ground in the sector made a vital acquisition, pushing off the Chaos forces that managed to loot as much as they could before making their escape.