Magnus, Margaret Fredulka’s son by King Niels of Denmark, had in 1125 claimed the Swedish throne as the eldest grandson of Inge the Elder at the death of Margaret's first cousin King Inge the Younger.

Magnus had been recognized by the Geats (Göterna) of Gothenland, but according to the Westrogothic law, had to be accepted also by the Swea, another tribe to the north of the Geats.

The Swea, however, had selected Ragnvald Knaphövde.

According to Saxo Grammaticus, Ragnvald had shown disrespect towards the Geats by not taking a Geat hostage.

As retaliation, Ragnvald had been murdered by Magnus's supporters not long after.

Magnus in around 1127 had married Richeza, daughter of Boleslaw III of Poland.

Magnus had in 1130 backed Boleslaw III in conquering Rügen.

The Polish forces, together with a Danish fleet, had compelled the Rani to recognize Polish rule over the island.

Magnus is not mentioned as King in the law of Västergötland and was probably ousted from Sweden by his successor Sverker I of Sweden around 1130.

Magnus had in 1131 arranged the murder of his cousin and potential rival for the Danish throne, Canute Lavard, in order to position himself as heir presumptive to his father King Niels.

Although Magnus is eventually backed by Niels, he finds himself in a civil war against Lavard's half-brother Eric Emune.

King Niels has his strongest base of support in Jutland, and the church also supports him.

Moreover, he has secured support from the Holy Roman Empire by agreeing to subordinate the Danish Archdiocese of Lund in Scania to the German Archdiocese of Hamburg-Bremen, which had prompted Archbishop Asser of Lund to support Eric.