From that time, with but one short period in the reign of William the Conqueror, the town rapidly grew in importance. It became the site of the East Anglian bishopric in 1075, when the see was removed from Elmham, and although that much-moved Bishop’s chair was again removed, to Norwich, nineteen years later, Thetford suffered little from that circumstance. If it ceased to be technically a city, it was a great town and a very stronghold of the Church. Although it has now but three churches, it owned twenty, so late as the time of Edward III., and the ruins of many of them can still be traced, proving the truth of those old records that tell of them. Seven were on the Suffolk side. These we might call suburban, but of them only that of St. Mary-the-Less is now extant. Its big sister, St. Mary-the-Great, stood adjoining the Grammar School, but only fragmentary walls remain. This was converted by Bishop Arfast into the cathedral of those nineteen years. Elsewhere in and around the town the shattered and shapeless walls of old-time ecclesiastical buildings abound, and the ploughman who drives his furrow across fields that were once streets, turns up mediæval tiles with the lack of interest that comes of constant use, or fervently damns the occasional abbot’s sarcophagus that dints his ploughshare. With the Crusades Thetford declined in population and fortune. Why, we do not know. It is not reasonable to suppose that the people went off in a body to fight the Paynim in the Holy Land. But the monasteries remained in being. Like the clinging ivy that flourishes even when the tree it has ruined is dead, they continued until Henry swept them away. They were four: that monastery, founded to commemorate the battle of Snarehill, which afterwards became a Benedictine nunnery; the Abbey, or Priory, founded by Roger Bigod in 1104; the Monastery of the Holy Sepulchre, Earl Warren’s foundation of five years later; and the Friary of St. Augustine, established by John o’ Gaunt in 1387. Besides these were numerous hospitals, together with the Manor House and the King’s Palace, used by sovereigns from Henry I. to James I. The only approach to Thetford in very distant times was doubtless by the Icknield Way, and for many centuries later that ancient track continued to be the chief road into and through the town on to Larlingford, where the existing highway from Thetford to Norwich falls into it. If we take up the line of the Icknield Way where, on page 189, we left it, we shall find it pointing straight through the Gasworks to the three bridges that now span the parallel stream of the Thet, a nameless intermediate rivulet, and the Little Ouse. These are (doubtless from the immediate neighbourhood of what is even now called “the Nunnery”) known as the “Nuns’ Bridges,” but one of them was formerly known as “Incelland” Bridge, and in that name we may perhaps find a distorted echo of “Icknield.”