Viking raids from 840 onwards contributed to the decline of Hamwic in the 9th century, and by the 10th century a fortified settlement, which became medieval Southampton, had been established. Following the Norman Conquest in 1066, Southampton became the major port of transit between the then capital of England, Winchester, and Normandy. Southampton Castle was built in the 12th century and surviving remains of 12th-century merchants’ houses such as King John’s House and Canute’s Palace are evidence of the wealth that existed in the town at this time. By the 13th century Southampton had become a leading port, particularly involved in the import of French wine in exchange for English cloth and wool. The Franciscan friary in Southampton was founded circa 1233. The friars constructed a water supply system in 1290, which carried water from Conduit Head (remnants of which survive near Hill Lane, Shirley) some 1.1 miles (1.7 km) to the site of the friary inside the town walls. Further remains can be observed at Conduit House on Commercial Road.