Complex sentence: First the princes of Gwynedd and then those of Deheubarth expelled the Normans, driving the English monks away when they re-conquered Cardigan in 1136, after a victory against the Normans at Crug Mawr, following the death of King Henry I in 1135.
Split into simpler sentences: First the princes of Gwynedd and then those of Deheubarth expelled the Normans. The Welsh drove the English monks away when they re-conquered Cardigan in 1136, after a victory against the Normans at Crug Mawr, following the death of King Henry I in 1135.