New Ross was in the territory of Dermot McMurrough and came to prominence when the Anglo-Normans conquered the region. The Norman knight William Marshall and his bride Isabella de Clare arrived during the early part of the 13th century. An earthen defensive structure called a motte was built at Old Ross in order to hold the newly conquered territory. A medieval borough sprung up around it - peopled by English and Welsh settlers. The arrival of Isabella and William is described in the "Chronicles of Ross", which are in the British Museum. It records that in 1189, Isabella set about "building a lovely city on the banks of the Barrow". The town's fortunes further increased when King John made William the Earl of Pembroke at his coronation in 1199. A year later, the Earl Marshal transferred the Norman capital of Leinster to Kilkenny and New Ross became the main port.