Medieval Scandinavia: The Downfall of the Kalmar Union

By Beñat Elortza Larrea

For the ninth and last article in the series, Beñat Elortza Larrea explores the internal tensions and conflicts that caused the dissolution of the Kalmar Union.

Increasing inter-Scandinavian entanglement, crafty marriage alliances and growing political ambitions had facilitated the formation of the Kalmar Union in 1397, whereby the kingdoms of Denmark, Norway and Sweden entered a personal union. The effective governance of such a large and diverse political entity, however, was fraught with conflict, as the Crown attempted to establish centralised control against the aristocrats’ wishes.


The two charters that were signed during the coronation festivities in Kalmar in 1397 aptly highlight the nature of the political tensions that characterised the internal politics of the Scandinavian union. The Coronation Charter, endorsed by both Margrete I and Erik of Pomerania, was a prime example of regimen regale; it envisioned a strong centralised rule of the three kingdoms where hereditary kingship was favoured (which stood against Danish and Swedish traditions of elective kingship), and the subservience of the aristocracy to the Crown was highlighted.

The Union Charter, on the other hand, argued for a practical union of the three kingdoms, whereby the observance of local customs and laws would be upheld, while the kingdoms would support each other when fighting wars or enforcing judicial decisions such as outlawry. The Union Charter likewise stated that shared elective kingship should be introduced – although preference should be given to the ruler’s firstborn son – and argued that foreign policy should be conducted following the advice of each realm’s aristocratic councils. Margrete and Erik, as mentioned, favoured the Coronation Charter; to further complicate the aristocracy’s position, the coronation document had been written in parchment and sealed with wax, while the Union Charter was only written on paper and sealed with ink, which undermined its validity as a binding agreement.


The reigns of Margrete I (d. 1412) and Erik of Pomerania (r. 1396-1439) were, unsurprisingly, an example of the application of direct royal rule, which exacerbated tensions among the aristocracy, especially in Norway and Sweden. Both rulers reigned primarily from their castles and residences in Denmark; they seldom visited the other kingdoms, and expected individual Norwegian and Swedish magnates – rather than whole councils – to come to them instead. Everyday administration was left in the hands of castellans, who managed their districts (len/län) in exchange for a cut of the taxes they collected; most of these administrators were often German and Danish throughout the union, which further undermined the participation of the royal councils. The attitude towards the local aristocracy is particularly well exemplified in Margrete’s advice to Erik during his trip to Norway in 1405: Erik should only meet local aristocrats – instead of summoning the entire council –, make sure his promises were vague and, most importantly, he was never to promise anything in writing.

The considerable resources and military power that the Kalmar Union could muster were put to good use during the early fifteenth century, as Erik engaged in protracted wars against Denmark’s traditional enemies, the Hanseatic League and the Duchy of Holstein. The successes of these conflicts, therefore, were mostly reaped by the Crown and the Danish nobility, while taxes and manpower to conduct the wars were collected in all three kingdoms.

By the 1430s, tensions in Norway and Sweden came to a boil: Swedes revolted in 1434, while areas of Østlandet in Norway rebelled in 1436. The causes of the Swedish revolt, led by minor aristocrat Engelbrekt Engelbrektsson, highlight the negative impact of Erik’s decision making: townspeople joined the rebellion because Hanseatic blockades prevented them from trading, while miners from Bergslagen likewise struggled to find a market for their ore; landowning peasants were enraged by new taxes levied to finance the ongoing wars; and the aristocracy, initially hesitant to join, eventually saw the revolt as an opportunity to demand meaningful political representation. The rebellion, already fragile from the outset due to the diverse – and clashing – interests of its participants, largely came to an end after Engelbrekt’s death in 1436, but the Swedish aristocracy elected a regent, Karl Knutsson Bonde, who ruled sporadically in the late 1430s whenever Sweden rejected Erik’s reign.

The Swedish aristocracy’s aversion to Erik as king, however, was shared by the elites of the two other kingdoms, especially after his foreign military campaigns proved ultimately unsuccessful. When the Scandinavian magnates refused to accept the nomination of Erik’s kinsman Bogislaw as the next king, Erik inexplicably exiled himself to Gotland. Unhappy of their ruler’s passivity, the Danes and Swedes deposed Erik in 1439 – the Norwegians followed suit in 1442 – and elected his nephew, Christoffer of Bavaria, in his stead. The changes to governance during Christoffer’s reign were significant, and the influence of the aristocracy behind these reforms is apparent. In Norway, the kingdom was divided into two large departments, which would be administered by local members of the council.

King Christopher in a contemporary drawing

In Sweden, on the other hand, the royal council became a standing body of governance, led by the archbishop; castellans – in practice – now owed their allegiance to the council; and a new realm-wide law was issued detailing that Swedish kings had to be “native-born”, rather than merely “native”. Christoffer’s reign was thus characterised by a sort of “council constitutionalism”, whereby the role of the aristocracy in governance became much greater; this period, nevertheless, was marred by widespread peasant unrest and localised famine, which made the king unpopular among the peasantry at large.

The relative stability of Christoffer’s reign, however, ended abruptly with his unexpected death in 1448. Following his passing, the Danes elected Christian I, while the Swedes favoured Karl Knutsson, who had served as regent in the aftermath of the Engelbrekt rebellion. Willing to capitalise on Christoffer’s successes, both kings issued accession proclamations that promised aristocratic participation in governance, as they strove to secure the nobility’s support and the Norwegian crown; while Karl was elected in Norway for a short time – 1449-1450 –, Christian I would ultimately secure the Norwegian throne for himself. Regardless of their promises, both kings’ reigns were characterised by a relative disregard towards aristocratic representation; while Christian remained relatively successful, partially due to military victories – he even was elected Swedish king between 1457 and 1464 –, Karl Knutsson was fiercely opposed by his opponents, and was deposed twice, eventually dying during his third reign in 1470.

Karl Knutsson’s death did not mean that Sweden was willing to accept Christian I as king, but the Swedish refusal did not mean that Christian was not going to try, either. The Swedish aristocracy elected Sten Sture the Elder as regent in 1470, and a Danish invasion followed shortly afterwards. Christian himself led a force of Danish men-at-arms and German mercenaries against Stockholm in 1471; as the Dano-German troops approached the city, they were attacked by Swedish forces from several sides at Brunkeberg. Caught by surprise, Christian was wounded shortly after the battle began, and the invading forces were routed. The resounding Swedish victory ensured Sten’s authority and status, and he governed the kingdom until 1497; during his three decades as regent, Sten Sture prevented more Dano-Norwegian encroachment from taking place, and likewise defended the Finnish borderlands from Novgorodian invasions.

St. George and the Dragon, built by Swedes to commemorate their victory at Brunkeberg. Photo by Tuomas Vitikainen / Wikimedia Commons

The death of Christian I in 1481, nevertheless, presented the Dano-Norwegian aristocrats with the opportunity to further their own agendas. Following the accession of Christian’s son Hans, the powers and role of the royal councils were set out in detail, especially in Denmark; in Norway, however, the smaller pool of aristocrats struggled to maintain large enough numbers to act as a coordinated bloc. Instead of directly opposing the nobility, Hans relied on his existing, structured and numerous bureaucratic apparatus to maintain his power, and he often favoured townspeople and landowning peasants in disputes, thus indirectly undermining the status of the high aristocracy. The balance between regimen politicum and regimen regale was harmonious enough, however, that even the Swedish aristocracy felt compelled to depose Sten Sture and elect Hans as king between 1497 and 1501; internal tensions between pro- and anti-Union nobles would flare up soon after, and Sweden would continue to be ruled by regents until the 1520s.

Hans was succeeded by his son, Christian II, in 1513. Unlike his father and grandfather, Christian II took a more autocratic approach to governance; as Hans’s plenipotentiary in Norway, he had actively worked to undermine aristocratic participation, and had appointed many Danes and Germans to Norwegian positions of power. One of Christian’s main obsessions, however, was the conquest of Sweden: he had participated in the Danish invasions of 1497 and 1501, and launched two more abortive attempts himself in 1517 and 1518. A third Danish invasion in early 1520 was finally successful when Swedish forces were defeated at Bogesund and the regent, Sten Sture the Younger, was killed. Stockholm capitulated in September, and Christian entered the town to be crowned. One of the conditions of the Swedish surrender had been a general pardon, which the union king had agreed to. Shortly after his coronation, however, Christian II had many of his opponents arrested on a technicality – they were accused of heresy because the archbishop of Uppsala had been on the Danish side –, tried and executed publicly.

Christian’s heavy-handed response galvanised support for the anti-Union aristocrats; the peasants and townspeople rapidly joined the growing revolt, and once-neutral noblemen, worried by their new ruler’s cruelty and suspicion, joined too. The opponents to Danish rule united behind Gustav Vasa, a young nobleman whose father had been killed in the Stockholm Bloodbath; partially owing to his own tactical aptitudes but also due to discontent against Christian II in Denmark and Norway, Gustav Vasa achieved a string of victories, and he was elected king in Strängnäs in 1523. Christian was deposed by the Danish aristocracy in the same year, and his uncle Frederick was elected in his stead; the Danish and Swedish kings met in Malmö in 1524, where the Danish-Norwegian ruler recognised Swedish independence. The Kalmar Union had come to its end.

Beñat Elortza Larrea is an Associate Professor at Nord University. His research interests include state formation in medieval Scandinavia, military history from a social perspective, and maritime societies in the Middle Ages. Click here to visit his page on


Click here to read more from Beñat’s series on Medieval Scandinavia