Richeza and her husband had their base in Denmark rather than Sweden. Alarmed by the popularity and Imperial support of his cousin Knud "Lavard", Duke of Schleswig, both Magnus and his father King Niels acted against Knud, who was murdered by Magnus on 7 January 1131. Knud's half-brother Erik rebelled against Niels and Magnus, but was defeated and took refuge in Norway, where he convinced the local nobility and the Holy Roman Emperor Lothair III to launch a retaliatory expedition against Niels. Meanwhile, Sverker I finally made the Swedes abandon Magnus in c. 1132, when he was busy with the civil war in Denmark; he then unified the country under his rule. Niels was defeated in the Battle of Fotevik (4 June 1134), and also lost his son Magnus who was slain during the battle. Niels escaped to Schleswig, where he was killed by the citizens (25 June 1134). Now a widow, Richeza returned to Poland, apparently leaving her two sons behind in Denmark.