1271-1273
The war between Emperor and pretender started in early 1271 when William II with most of his allies from the empire invaded the Austrian lands of Ottokar II, linking up with the forces of Stephen V of Hungary, near the important city of Vienna. Ottokar II’s response was as swift as possible; his own forces from Bohemia and Moravia marched south, but not committing to a pitched battle, meanwhile he waited for his own allies to come to his aid, Boleslaw V the High duke of Poland being the most important. The forces arrayed against each other in the summer of 1271 was immense, with William II and Stephen V having the larger of the two, yet it was not the full forces that both sides could muster. Both sides had left plenty of troops on their northern border, especially Boleslaw V and his dukes kept considerable forces in Poland. Both sides courted Erik IV extensively, and it was only a matter of time before the Danish king would plunge his realm into the conflict.
While both sides waited for the eventual decision, the fighting raged on in the Austrian lands of Ottokar II, during 1271 reinforced by Boleslaw V, Ottokar II had a series of inconclusive victories against William II, however, he had succeeded in regaining much of his possession opening up for potentially more soldiers as the minor nobility in Austria flocked to his side. These new recruits would play an important role as the new front of the war opened up in 1272, having made a decision Erik IV, invaded Brandenburg, having used 1271, to gather mercenaries and his own troops, he divided his force, one going to Schwerin, the other to Stettin in Pomerania. Both armies would use the Oder and Elbe Rivers as supply lines, and as such, both of the Danish armies pushed over the borders in April 1272. However, these two armies were not the only headaches for Ottokar II and his allies, Duke Konrad II of Mazovia, the sole Duke after the unexpected death of his brother three years earlier. Had too gathered an army, seeded with men from Denmark’s province of Prussia, while Konrad II cared little for the empire, he did care about Boleslaw V that had defeated his Grandfather Konrad I some 30 years earlier in the conflict in which of them should be the High Duke.
As such, the reinforcements from Ottokar II’s southern duchies had to replace the men that Boleslaw V had supplied Ottokar II for his bid for the throne. As Boleslaw V when he got the message a few weeks later departed with all his troops to defend his claim as the High Duke of Poland. Erik IV had decided not to lead the armies himself; therefor Duke Valdemar of Holstein-Benburg* would lead the thrust from the Elbe River, while Prince Jaromar III of Rostock would lead the more eastern push into Brandenburg and later into Poland. The objective, defeat the Margraves of Brandenburgs forces, occupy their land, and then march into Poland and Bohemia simultaneously, putting pressure on Ottokar II. Brandenburg was not ruled by a single ruler, the territory was split in two, Brandenburg-Stendal and Brandenburg-Salzwedel furthermore each of these two territories had four co-rulers all the sons of Either John I or Otto III which together had co-ruled Brandenburg between 1220 and 1266.
As the two large Danish armies entered their territory the eight rulers of Brandenburg tried to resist, yet could not agree on who should be in command of their combined troops, to make the matter worse, the western part of their land, Altmark had been invaded by troops from Braunschweig-Lüneburg. The result was that the troops that they could muster were combined intro three small armies that were easily defeated by Valdemar of Holstein-Benburg and Jaromar III of Rostock. Brandenburg was occupied in a matter of weeks and the two Danish armies marched on. Denmark however, would not enjoy the luxury of not being invaded themselves, from the east the Merchant republic of Novgorod and the City of Pskov invaded the Estonian duchies and the Danish Livonian province. The two republics hoping that the Kingdom’s resources would be spent on the war in the south saw it as a chance to counter increased Danish influence on their trade.
While much can be said about Erik IV as a ruler, he had expected for just such a scenario to happen, and was therefore not completely surprised by the development. His two armies to the south consisted of most of the levies of his dukes, and levies from Prussia, however the levies of Livonia had not been called up. They would be the first line of defence together with the few fortification actually build on the border between the two forces, Narva being the only border castle actually holding on until reinforcement came from Denmark. More importantly than the Livonia levies not being called up, was that Erik IV had not evoked the Ledgang in Denmark proper, and that was exactly what he did in the winter of 1272. Not the new kind that his father Valdemar III had used extensively to pay for his wars, no, the ledgang of 1273 was that of old, like his grandfather Valdemar II and his father Valdemar I had used to conquer the Baltic. Amassing the troops at Vordingborg, the royal castle of Denmark, where the King spent his time, when not visiting other nobles, Erik IV gathered another large army, arguably by far the worst in equipment, yet quantity is in itself a virtue, besides the army did not have to fight the ironclad knights of the west. Sailing toward the eastern Baltic in the summer of 1273 the army under the command of Erik IV himself arrived near the Narva River taking the army of Novgorod and Pskov by surprise as they were in an ongoing siege against the Castle of Narva. While Erik IV was successful in lifting the siege, the army of Novgorod retreated to the east mostly unharmed.
To the west, the situation looked bleak for Ottokar II, having suffered a major loss to William II in a large battle outside the gates of Vienna, due to being severely outnumbered by Boleslaw V leaving. As he returned to the Bohemian crownlands to try to gather a new army, he got the news that Duke Valdemar of Holstein-Benburg and his Danish army had entered his lands from the north. In Poland the situation was better, Boleslaw V had arrived home in time, defeating the Mazovian-Danish army under Duke Konrad II marching along the Vistula river towards Krakow, however the Army of Prince Jaromar II of Rostock has entered the prosperous lands of Silesia wreaking havoc.
*Previsuly Bengerndsborg, yet known as Benburg to the peasantry and will in time officially be known as such.
(although I did already remember the word Hav from a trip to Copenhagen and the Havfruen statue in the harbour.