After the Saxon invasion, Sarobyrig, as it was then called, probably assumed its present outline so far as the foundation of the walls are concerned.  That a mint of Canute (who according to one tradition, died here and not at Shaftesbury) and again of Edward Confessor was set up, and that the town became the seat of the Bishop of Sherborne, was a proof of its established importance.  The smaller central mound of the citadel itself would appear to have been a work of the Normans, who divided the space occupied within the outer defences into two parts; that on the east belonging to the military works, and the western half pertaining to the Bishop and having within it the original Salisbury Cathedral.  Here was instituted by Bishop Osmund the new English ritual or “use of Sarum,” and here commenced those endless squabbles between clergy and soldiers that at last resulted in the men of peace leaving the fortress city.

  ("Quid Domini Domus in Castro, nisi foederis arca
  In Tempho Baalim?  Carcer uterque locus,
  Est ibi defectus aquae, sed copia cretae,
  Saevit ibi ventus, sed philomela silet.”)

The commission to inquire into the proposed change was appointed by the Pope in 1217, and from this year begins the rapid decay of Old Sarum.  The Cathedral was dismantled and much of the material was used in the new structure in the plain.  That the original was a noble building existing records and ultimate discoveries amply prove.  The ground plan was well seen in the dry summer of 1834, when measurements were taken and the total length found to be 270 feet.  The first church was seriously damaged by a thunderbolt five days after its consecration, and the original plan was much elaborated in the rebuilding—­

“So gret lytnynge was the vyfte yer, so that al to nogt
The rof of the chyrch of Salesbury it broute,
Ryght evene vyfte day that he yhalwed was.” 

          
                                            (Robert of Gloucester.)

Of the castle not so much is known.  Leland says in 1540:—­“Ther was a right fair and strong castella within Old-Saresbyri longing to the Erles of Saresbyri especially the Longerpees.  I read that one Gualterus was the first Erle after the conquest of it.  Much ruinus building of this castelle yet ther remayneth.  The dich that environed the old town was a very deepe and strong Thynge,” and again “Osmunde, erle of Dorchestre, and after Bishop of Saresbyri, erected his Cathedrale church ther in the west part of the town; and also his palace; whereof now no token is but only a chapel of Our Lady yet standing and mainteynid....  Ther was a paroch of the Holy Rode beside in Old-Saresbyri and another over the est gate Whereof some tokens remayne.  I do not perceyve that there are any mo gates in Old-Saresbyri than 2; one by est and another by west.  Without eche of these gates was a fair suburbe.  On the est suburbe was a paroche church of S. John; and ther yet is a chapel standing.  The river is a good quarter of a myle from Old-Saresbyri and more, where it is nerest on to it, and that is at Stratford village south from it.  Ther hath bene houses in tyme of mind inhabited in the est suburbe of Old-Saresbyri; but now there is not one house neither within Old-Saresbyri nor without it inhabited.”