The Bishop's Palace stands to the north of the cathedral, and was formerly connected with it by a vaulted passage, Herbert, the founder, built the first palace, of which portions are incorporated in the present building. Bishop Salmon (1299-1325) in 1318, according to the patent rolls of the twelfth year of the reign of Edward II., obtained licence to buy a piece of land 47 perches 4 feet in length, and 23 perches 12 feet in breadth, to enlarge and rebuild thereon the palace of Herbert. He also built a chapel, and the great hall, measuring 120 feet from north to south, and 60 feet wide, with kitchen, buttery, and offices at the west end. The grand ruin somewhat to the east of the palace now is supposed to have formed part of the entrance to this hall. It was, however, too large to keep up, and so was leased by Bishop Nykke, just before his death in 1535 to the mayor, sheriff, and citizens, so that the Guild of S. George might hold their annual feast there. Later on it became a meeting-house. The present private chapel of the bishop was built by Bishop Reynolds in 1662 across part of the south end.
To the north of the nave of the cathedral, and on the west side of the palace, was an open area called the green-yard, and in Sir Thomas Browne's "Works," vol. iv. p. 27 (London, 1835) is an account of the combination sermons which were preached here in the summer prior to the Reformation.
"Before the late times the combination sermons were preached, in the summer time, at the Cross in the Green Yard where there was a good accommodation for the auditors. The mayor, aldermen, with their wives and officers, had a well-contrived place built against the wall of the Bishop's palace, covered with lead, so that they were not offended by rain. Upon the north side of the church, places were built gallery wise, one above another, where the dean, prebends and their wives, gentlemen, and the better sort, very well heard the sermon: the rest either stood or sat in the green, upon long forms provided for them, paying a penny or half-penny a-piece, as they did at S. Paul's Cross in London. The Bishop and chancellor heard the sermons at the windows of the Bishop's palace: the pulpit had a large covering of lead over it, and a cross upon it; and there were eight or ten stairs of stone about it, upon which the hospital boys and others stood. The preacher had his face to the south, and there was a painted board of a foot and a half broad and about a yard and a half long hanging over his head, before, upon which were painted the names of the benefactors towards the Combination Sermon which he particularly commemorated in his prayer...."
On the north side of the cathedral, in the seventh compartment of the aisle from the west end, the walled-up entrance to the green-yard is to be noticed.
There is no doubt that this space was originally the cemetery of the monks, and Harrod quotes from the Chronicle of John de Whethamsted to that effect. A stone coffin lid found here in 1848 goes to confirm this.