Hugh's army had already marched as far as the river Seine and stopped to recover in the county of Reims when the news of his first misfortune reached him: Norsemen had sailed up the River Seine into the heart of France and landed a sizable raiding force in the county of Amiens, thus standing directly between Hugh's army and Vexin. Seeing marauders so close to the throne in Paris was surprising and worrisome and Hugh, if he was not already operating with a precariously small army, would have certainly liked to drive the northerners back into the sea. However, the lands of Burgundy were rich in soil and not in men, and so instead the Duke was forced to divert northwards through the westernmost counties of Germany, and then double back around through the duchies of Flanders and Normandy, finally travelling eastwards along the Seine towards Vexin.
The Vexinois defenders had been expecting Hugh to attack from the northwest, and were thus surprised when their scouts spotted a bedraggled group of Burgundians marching from the
east along the banks of the Seine. The Karlings defending Vexin--a small army comprised of troops from Vexin, as well as some soldiers from the county of Vermandois, which was also under Karling rule--assumed that Hugh had attempted to drive through the Norse raiders and lost most of his army, and so the commander of the defenders sent a force of levees to engage what appeared to be the remaining Burgundian forces. As soon as the Karling levees engaged the small force of Burgundians, Hugh's main host charged into the melee, trapping the majority of the Karling soldiers against the banks of the Seine and routing the enemy force.
With so many defenders lost in the failed sally, Hugh managed to lay siege to the province with little incident. The majority of towns in the county surrendered shortly thereafter, and within two years the main castle of Pontoise had fallen, forcing the count of Vexin, still in his minority, to officially surrender the county to Hugh by October of 879.
Hugh had originally anticipated that the count of Amiens, also a member of the Karling family, would also have contributed to the defense of Vexin, but the presence of the large Norse raiding party had preventing Amiens from formally entering the conflict. As a result, there was nothing preventing the Duke of Burgundy from pressing his claim on the county of Amiens without delay. However, the two years spent laying siege to Vexin had thinned Hugh's army, mostly from defection and disease, and so it was three months before Hugh felt comfortable enough to march eastwards and declare war on Amiens, who was again joined by the count of Vermandois.
Hugh's army had engaged the Karling's directly, and the superior numbers of the Burgundian forces, especially the highly mobile units of lighter infantry, turned the battle into a second rout, with only fifty troops from Vermandois remaining. The count of Amiens, also in his minority, allegedly attempted to surrender the county to Hugh immediately after hearing report of the battle. However, Hugh continued the war, even after successfully laying siege to Amiens, on the grounds of eliminating the remaining Karling forces. Despite his respect for the count of Vermandois's attempt to help his kinsmen, Hugh could not allow such a challenge to his authority go without punishment. As such, Burgundian troops entered Vermandois itself and engaged what was left of the Karling troops, leaving no survivors; Bourgogne control over the Valois region was solidified with the blood of Vermandois.
Hugh again returned home to Dijon, this time victorious in his expedition. He was, however, not yet entirely comfortable with his position. He had spent almost four years abroad, and it had become evident that Hugh would not live to see the Welfs removed from the Kingdom of France. However, Hugh had dedicated much of his time to ensure that the Duchy would fall into capable hands. His firstborn son, Charles, had been raised in both the diplomatic and military arts, and surpassed his father in both fields. Furthermore, he was also engaged to the current Duchess of Anjou, ensuring that a major source of power for the Welfs would instead fall into the hands of the Bourgogne's.
The personality of Hugh changed dramatically after returning from the northern expedition. Hugh's second wife, despite their loveless union, had surprised and pleased Hugh by producing his first daughter. The castellan of Dijon's last entry concerning the reign of Hugh included a note that describes Hugh as "a man torn between the satisfaction with his numerous successes in the expansion of the prestige and control of Burgundy and the failure to achieve his most prized goal of seeing the [Welfs] expelled from Francia."
As Hugh continued to age, his mental health continued to decay, and management of the duchy gradually shifted into the hands of Charles. Hugh's last major decision was a second expedition northwards, this time attacking the duchy of Flanders for control over Artois, which Hugh had ordered his chancellor to go and produce Burgundian claims for. The Flemish levees, although usually greater in number than Burgundy's, had been worn down by constant raids from the Norse, and barely numbered over one thousand.
By the Spring of 885 a force of almost
two thousand Burgundian troops had reached the Flemish province of Boulogne, and the two duchies promptly met in battle outside of Terwaan in Artois. The Flemish troops were handed a heavy loss, although more than two hundred troops managed to escape the slaughter. The survivors were chased back to Boulogne, where they were shattered in the Battle of Saint-Pol. Charles, now in full command of the Burgundian troops, was met with widespread approval for his first successful operation.
His elation was, however, tempered with the direst of news. While his son and armies were away in the north, Duke Hugh of Burgundy had passed, leaving the title to Charles.
