In early 1299 he married secondly with Euphemia, daughter of Vitslav II, Prince of Rügen, who in 1301 bore him his only legitimate daughter, Ingeborg Håkonsdotter, since 1312 wife of duke Eric Magnusson of Sweden, a younger brother of King Birger of Sweden. Their son, Magnus Eriksson would succeed Haakon V as king of Norway.
Wars of the Rügen Succession (1326–1328; 1340–1354), after the death of prince Vitslav III of Rügen Wars of the Loon Succession (1336–1366), after the death of count Louis IV of Loon Hundred Years' War (1337–1453), indirectly after the death of king Charles IV of France