 Complete the following phrase:  In 1136 Morgan together with his brother Iorwerth murdered Richard FitzGilbert de Clare, the Anglo-Norman lord of Ceredigion, in an ambush during the Welsh revolt after the death of King Henry I. He then captured Caerleon and Usk Castle, thus gaining control of Upper Gwent and Llenfennydd. Although he only ruled over a small territory, he called himself king from that point. Since the neighboring Norman Marcher Lords were themselves involved in the 