Complex sentence: Comparison can be made with the earlier Viking migration of 985 AD when 14 of 25 longships reached their Greenland destination from Iceland, a distance of about 320km, according to the Icelandic sagas.
Split into simpler sentences: Comparison can be made with the earlier Viking migration of 985 AD. At that time, 14 of 25 longships reached their Greenland destination from Iceland, a distance of about 320km, according to the Icelandic sagas.