Complex sentence: From earlier property disputes and such, Lady Inger was an enemy of the Catholic prelate Olav Engelbriktsonn, primate of Norway and archbishop of Nidaros, who also rivaled over Norway's government against lady Inger's eldest son-in-law lord Vincents Lunge.
Split into simpler sentences: From earlier property disputes and such, Lady Inger was an enemy of the Catholic prelate Olav Engelbriktsonn, primate of Norway and archbishop of Nidaros. Archbishop Engelbriktsonn was also a rival in Norway's government with Lady Inger's eldest son-in-law Lord Vincents Lunge.