Eric of Pomerania, ruled over the Kalmar Union from 1396 until 1439. He was initially co-ruler with his great-aunt Margaret I until her death in 1412. Eric is known as Eric III as King of Norway (1389–1442), Eric VII as King of Denmark (1396–1439) and has been called Eric XIII as King of Sweden. Eric was ultimately deposed from all three kingdoms of the union, but in 1449 he inherited one of the partitions of the Duchy of Pomerania and ruled it as duke until his death in 1459. His epithet of Pomerania was a pejorative intended to insinuate that he did not belong in Scandinavia.

The Kalmar Union was a personal union in Scandinavia, agreed at Kalmar in Sweden as designed by widowed Queen Margaret of Norway and Sweden. From 1397 to 1523, it joined under a single monarch the three kingdoms of Denmark, Sweden, and Norway, together with Norway's overseas colonies.