There is no evidence to prove that the wall built across the country by the Roman invaders extended quite as far as Dumbarton. It cannot be supposed, however, that they ignored the strategic importance of the Rock, and failed to occupy a position which was practically the key to the West of Scotland. As to the existence of a fort during the period that followed the evacuation of Britain by the Romans, there can be no doubt. The Welsh chronicles refer to it under the name of Alclud, or Alcluid, that is, "the Rock of the Clyde". Further, it is recorded in the _Historia Britonum_ "that, as the result of a battle fought between the Britons and the sons of Ida, in 573, the greater part of the North Country fell into the hands of a king called Ryderchen, who chose as his seat the stronghold known to the Gaels by the name of Dunbraton," or the fort of the Britons--the original form of the modern Dumbarton. In confirmation of this sixth-century occupation of the Rock, there is a passage in the life of Columba where Adamnan states that the saint was consulted by King Rodorcus, son of Totail, who reigned on the Rock of the Clyde.[234] Under the date of 870, the _Annals of Ulster_ and other Irish chronicles record that the Norse leaders Amlaiph and Imhar laid siege to Strathclyde, in Britain. Besides cutting off all provisions, they were able to draw off, "in a wonderful manner", the water of the well within the fortress. By reducing the defenders to such a state of weakness that they could not repulse their assailants, hunger and thirst gave the Norsemen possession of the fortress.[235] At the time of the dispute between Bruce and Baliol, the Castle of Dumbarton was in the keeping of Nicholas de Segrave. By virtue of the right that he claimed as feudal superior, Edward I commanded the fortress to be handed over to the competitor in whose favour he had pronounced. It was not till 1296, however, that the English King was able to enforce his order, and to appoint a Governor of his own choosing. This was Alexander de Ledes, whom he also made Sheriff of the County. De Ledes was succeeded by Sir John Menteith, who earned an unenviable notoriety by the betrayal and capture of Wallace, and to whose keeping the illustrious prisoner was entrusted prior to his being removed to London. The Scottish hero's sword was long preserved as an historical relic in the Castle. An entry in the Accounts of the Lord Treasurer shows that it was there at the time of James IV's visit, in 1505, and that the King paid for "binding of Wallass sword with cordis of silk, and new hilt, and plomet, new skabbard, and new belt to the said sword".[236] It was not till 1888 that this interesting memorial of the patriot was transferred to Stirling.