with the Viking threat. But repeated Norman incursions into the interior, reached by river and stream, caused great insecurity. So in the 9th century the Duke of Poitou built the fortified city of Surgères, also called the of Benon, with "a tower that stood in the middle of a square, encircled by two paths and three moats". At the end of the 11th century, the Counts of Poitou started to pay attention to the forsaken backwaters of the region, and made them a priority. Above all, they encouraged powerful abbeys to be founded after clearing the Forest of Argenson. () Abbey was built in Benon, being the first Cistercian abbey to be founded in Aunis, and an active participant in the forest clearing movement. The clearings opened the way into the ancient forest to set up villages and farming (wheat, oats, barley) and to plant vines. The powerful monasteries, backed up by the lords, helped with the clearings of Aunis in the 11th century. But it is mostly during the 12th and 13th centuries that these earthworks were completed; much later that they became the "plain" of Aunis. On the coast, the salt waters had become amenable and created Aunis's wealth, and by the end of the 11th century its prosperity was assured. Châtelaillon rapidly became the largest fortified city in Aunis and an important port for the transport of salt from Aunis, and wine from Saintonge. After the demise of Châtelaillon in 1130, La Rochelle quickly rose to prominence and became the new capital of Aunis: "The demise of Châtelaillon dates to 1130, but it was only in 1144 that Alon family control was removed. A party assembled at Mauléon, the nearest island to Aunis, and they built the new town of La Rochelle there starting in 1151". The province was thus controlled in 1130 by William X, Duke of Aquitaine, bringing the dowry of Eleanor of Aquitaine to Louis VII of France, then, after their divorce and her remarriage, to King Henry II of England. Aunis was returned to the French with Louis VIII of France in 1224, but was restored by the Treaty of Brittany in 1360 by John II of France. This yoke was shaken off in 1371, and the province restored to King Charles V of France. Birth of the province In 1374 the King officially separated Saintonge in 1374 and set up Aunis: "In