Complex sentence: In the early 1050s Earl Siward turned against the Scottish ruler Mac Bethad mac Findlaích ("Macbeth "), whom he defeated in battle in 1054, an adventure which more than half a millennium later earned him a place in William Shakespeare's"Macbeth".
Split into simpler sentences: In the early 1050s Earl Siward turned against the Scottish ruler Mac Bethad mac Findlaích ("Macbeth "). This was the adventure which more than half a millennium later earned him a place in William Shakespeare's"Macbeth".