Complex sentence: The arrival of the Vikings on June 8th 793 on the shores of Northeast England, was an unprecedented attack that shocked the whole of Europe, a raiding party from Norway attacked the Monasic settlement on the Holly Island of Lindisfarne.
Split into simpler sentences: The arrival of the Vikings on June 8th 793 on the shores of Northeast England, was an unprecedented attack that shocked the whole of Europe. A raiding party from Norway attacked the Monasic settlement on the Holly Island of Lindisfarne.