The Hundred Days War (実録・百日戦役, jitsuroku: hyakunichi sen'eki) is a book that can be found in Trails in the Sky FC. Joshua Bright gives it to Estelle Bright at the night of their stay in the Kingfisher Inn near Ruan's Valleria Lakeshore during Chapter 1 of FC.
<Outbreak of War>
In spring, 1192 of the Septian Calendar, a single cannon-shot shook the Haken Gate, situated in the northern part of the Liberl Kingdom. This marked the beginning of an invasion later known as the Hundred Days War, and the moment in which the raging golden stallion assailed the noble white falcon.
During this time, the Haken Gate was little more than a reinforced medieval rampart. It easily succumbed to the round fired by one of the Empire's Reinford Company-built orbal tanks, leaving a section of the aged barrier fractured beyond repair.
And as the Liberl Kingdom's other defensive walls were hit in succession by a fusillade of cannonballs, they too fell under the explosive impact and were reduced to a mountain of rubble.
<Declaration of War>
At about the same time that the first cannon-shot was fired, a single letter from the Erebonian Embassy located in the Royal City was delivered to Queen Alicia. More specifically, it was a writ containing a declaration of war by the Erebonian Empire upon the Liberl Kingdom.
In terms of diplomatic wisdom, the propriety of the declaration was established by being handled prior to the preemptive strike, but in this instance, there was hardly a difference in time between when the two occurred. In short, firing the first shot at the exact moment war was declared on the Liberl Kingdom made it possible for the Erebonian Empire to guise their preemptive strike as one of legitimacy when the first bombshell hit. This could be referred to as a new diplomatic war tactic, though one incapable of being employed without a meticulous level of planning used in concert with an orbal communication system.
After the destruction of the Haken Gate, the Imperial Army began its invasion of Liberl in earnest. Overall its troop strength was made up of thirteen divisional units. This proved to be roughly half of the Empire's entire military force, and was such a massive deployment that it exceeded three times that of Liberl's entire Royal Army.
Within a month after the outbreak of war, the Imperial Army had occupied nearly all of the Liberl territory. Only the Grancel region and Leiston Fortress, situated just off the shore of Valleria Lake, remained in opposition. So rapidly were these blitz tactics carried out that even the Calvard Republic, an ally of the Liberl Kingdom and long-time rival of the Erebonian Empire, never had the opportunity to dispatch auxiliary forces to aid its partner.
However, in a following attempt by the Imperial Army to take direct control over the Zeiss Central Factory and Malga Mine, they instead found themselves on the verge of being forced to surrender to Queen Alicia, who remained entrenched within the Royal City.
<Staging a Counterattack>
Two months following the outbreak of war, the battle situation was altered in a way which no one could have previously anticipated.
Unbeknownst to the Erebonian army, three patrol ships were quietly being developed behind the walls of Leiston Fortress. Upon completion, they were put under the direction of veteran commander, General Morgan, and a large scale counterattack was launched.
These patrol ships, shielded by armor far superior to the tanks of their imperial counterparts and mounted with a substantial amount of high-performance orbal weaponry, had also managed to boost their speed to over 1800 selge per hour. Using these crafts-- an inde- pendent mobile force lauded as the elite of elite-- Liberl's forces mounted an attack and quickly recaptured the checkpoints connecting the various regions. And as this strike was underway, they simultaneously launched an amphibious attack from Leiston Fortress and, one by one, defeated the remaining isolated imperial divisions.
<The End of Hostilities>
After just three months following the outbreak of war, the larger part of the Imperial Army's remaining divisions finally surrendered. However, as capitulation was at hand, there were indications of a surge of further reinforcements from the imperial homeland-- a move which galvanized other continental nations to follow suit and join the Republic of Calvard in supporting Liberl. Together they lambasted the Empire, and a formidable group of allied forces began to materialize.
Amidst all the chaos the Septian Church, in cooperation with the Bracer Guild, called for an armistice, and after approximately one hundred days from the start of the war the hostilities came to an end. In the following year of 1193, in the Erbe Royal Villa on the outskirts of the Royal City, a peace treaty was signed by both the Liberl and Erebonian sides. Although no indemnification was made, an official apology was offered up by the imperial government as they expressed that they had, '...made a grievous error attributed to a tragic incident occurring within (their) borders.'