In the story of Bran we get the constantly recurring idea of a palladium. It seems to be referred to again in Merlin's prophecy, "Till the buried kings be exposed to view in London." Some object like the statue of Pallas in Troy, and the shield of Numa in Rome, was, as it were, the soul of a city. In Geoffrey of Monmouth a brazen horse on Ludgate figures as the protecting talisman; London Stone may have had some such mystical meaning attached to it by the Saxons (see p. 181), and the Shrine of Erkenwald in St. Paul's was the sacred heart of the city in the Middle Age. That the idea of a palladium was known in Britain is proved by the case of the sacred stone of Scone--the Coronation Stone. A similar story is told of the tomb of Iver in the Saga of Ragnar Lodbrok. William the Conqueror had to break it down before he got the victory at Hastings. _Southwark or the Borough._--The Burgal Hidage, a document which has recently been critically examined,[112] containing "a list of ancient fortresses," which dates from "the days of Edward the Elder at the latest," gives us the earliest reference to Southwark. "It sets forth, so we believe, certain arrangements made early in the tenth century for the defence of Wessex against the Danish inroads. It names divers strongholds, and shows how in the great age of burh-building they had wide provinces which were appurtenant to them." Amongst the burhs named comes Sutheringa-geweorc, in a position which is satisfied by Southwark.[113] Dr. Maitland concludes generally that the boroughs had their origin in such royal burhs founded for national defence. "The borough belongs to the genus villa (_tun_), but it was in its inception royal." The South-work was evidently a _tête-du-pont_, and became a royal borough. By means of special privileges such burhs, like the bastides of Edward I., attracted a heterogeneous population of traders, and Southwark became the great "cheaping town" of the _Heimskringla_, and "the Borough" _par excellence_ to this day. In the Pipe Roll of 1130 it stands with Guildford as the second borough in Surrey, and it returned members to Parliament from the first. It must have been protected by a ditch, and remains of this, or of Cnuts dyke, might have given rise to the tradition recorded by Stow that the course of the Thames had been altered when the bridge was built by a trench cast from Rotherhithe to Battersea. The older Maitland seems to have gathered some evidence of its palisaded bank.[114] Even in the time of the Confessor the "burghers" are spoken of. Some coins of Ethelred II. bear the mint mark of Southwark: this also is a sign of being a royal burh. The whole of Surrey seems to have been under contribution for the maintenance of Southwark and Eashing [bridge?]. The churches of Southwark are of considerable antiquity. The parish church of St. Olave is mentioned 1096, and St. George's and St. Margaret-on-the-Hill can be traced back to about 1100.