Complex sentence: The two kingdoms were united in a personal union under a child king, with the king's mother as his guardian; later, Olav had designs on the throne of Sweden (in opposition to Albert of Mecklenburg) from 1385 until 1387.
Split into simpler sentences: The two kingdoms were united in a personal union under a child king, with the king's mother as his guardian. Olav also had designs on the throne of Sweden (in opposition to Albert of Mecklenburg) from 1385 until 1387.