Complex sentence: During the early medieval period, pilgrims traveled to the shrine of St. Olaf at Trondheim; those from Sweden passed via Eidskog, Vinger (now Kongsvinger) and Elverum up the Glomma river valley.
Split into simpler sentences: During the early medieval period, pilgrims traveled to the shrine of St. Olaf at Trondheim. From Sweden it passed via Eidskog, Vinger (now Kongsvinger) and Elverum up the Glomma river valley.