Fourth Legion The Fourth Legion of Black Marsh was a division within the Imperial Legion . Initially led by a " young and charismatic " commander named Augurius Bucco , it fought during the Imperial invasion of Black Marsh , known as the " Blackwater War . " First campaign . Equipment . During the Blackwater War , which started in 1E 2811 , it became obvious to Imperial forces that the Fourth Legion ' s equipment was not intended for use in the swampy , moist climate of Black Marsh ; much of their armor was heavy and prone to rust . By late 1E 2812 , some Legionnaires had completely abandoned significant portions of their armor due to the lack of comfort stemming from the weight and subsequent intense heat caused by the armor . Tactics . Like their extremely inadequate armor techniques , the Fourth Legion ' s battle tactics proved disastrous in Black Marsh . Due to the region ' s typically swampy and inhospitable geography , the Legion had serious trouble with organization , especially during battle . The uneven and thick terrain meant that their use of " rigid line organization " in clearer areas was no longer applicable . The lack of unity meant giving orders on the battlefield was difficult . This in turn led to numerous failures in battle and many desertions . Thousands of Legionnaires of the Fourth Legion would die during the war because of the Legion ' s unpreparedness . Decimation . By the year 1E 2816 , all that was left of the Fourth Legion were six ragged cohorts . Morale steadily declined as losses in battle , disease , and disappearances afflicted the Legionnaires . By 1E 2820 , the Fourth Legion had been almost entirely destroyed , and the few remaining soldiers could not last much longer . At one point , the leader of the Fourth Legion , Augurius Bucco , was almost deposed as commander , and orders to withdraw from the deep swamps of Black Marsh were issued . The remnants of the Legion — just over 350 soldiers — made a stop at an ancient Argonian pyramid known as " Xi - tsei " on the tenth day of withdrawal , with the intention of continuing the retreat onward to Cyrodiil . However , on the night of Last Seed 14 , 1E 2820 , the few surviving troops were all killed , presumably by Argonian forces . Mysteriously , the bodies of roughly 150 of them were never discovered , and no indication whatsoever of their whereabouts was recorded . Second campaign . After word of the Fourth Legion ' s utter annihilation reached Cyrodiil , the Fourth Legion was reconstituted by the Imperial Council , this time commanded by General Regulus Sardecus . Thus began the second campaign of the Blackwater War . Reorganization . Under Sardecus ' leadership , the newly recreated Fourth Legion quickly resumed fighting in Black Marsh , regaining all previously - lost territory by 1E 2823 . This is largely credited to Sardecus ' orders that Legionnaires were to switch out their metal armor for " padded leather jackets , " which were more suited to the Argonian climate . Additionally , efforts were made to improve communications between Imperial quartermasters , scouts , and Argonian " irregulars . " The Legion learned how to live off the land rather than rely purely on imported supplies . Sardecus also decreed that Centurions and Legates were to be allowed more control over their own groups of soldiers , thus allowing for more organized independent fighting . Sardecus was also quick to strip a soldier of their rank if they did not adhere to his methods . This system served to both improve the efficiency and the morale of the Legionnaires . Successes . The most successful way that Sardecus overcame his opponents was actually through diplomacy rather than brute force . Unlike his predecessor , he was aware that the Argonians were not in fact a fully unified , barbaric people . Many influential tribes who were considered " disenfranchised " ( such as the Archeins and Shoss - kaleel tribes ) were offered various rewards for assisting the Legion in its conquests . In some circumstances , even full military alliances were formed . nearly tripling the Legion ' s manpower , and at last giving the Imperials a great advantage in the war . The militaristic strategy of Sardecus and the Fourth Legion worked on the idea that the Argonian swamps were the most dangerous force to be faced . The strategy also focussed on rendering sources of food , cover , and travel useless to the Argonians . Second retreat . After setting ablaze an expansive underground tunnel system , the Legion realized that the tunnels had been much father - reaching than anticipated ; what started as just another attack led to much of the region being entirely engulfed in flames . As a result of the fire , hundreds of Legion soldiers and Argonians alike were devastated by frequent deaths by " swamp lung " and gas explosions , leading to a second retreat and subsequently Sardecus ' death by an " infected wound " during the return to Cyrodiil . Third campaign . The Fourth Legion ' s strategy had again been altered by 1E 2833 , at which point General Lucinia Falco had succeeded Sardecus as commander of the Fourth Legion . Falco split up her soldiers into hundreds of small , highly lethal groups , later called " redbelts , " in place of the full Legion . The prowess of these so - called " redbelts " was strengthened by the experience and knowledge of " grizzled swamp veterans , " some of whom had been fighting in the war since the second campaign . Although much progress was made at the beginning of the campaign through the use of this system , captured territory was held very loosely by the Fourth Legion . Eventually , the conflict escalated to an all - out guerrilla war , and tactics such as fierce intimidation were often used . By late 1E 2836 , however , the Argonians abruptly ceased fighting , and by 1E 2837 the Empire had effectively secured full control over the region .