On the Pipe Rolls there are frequent entries of sums for the repairs of the "King's houses in the Tower," probably the great hall "x," with its kitchen and other appendant buildings; "of the chapel" (obviously that of St. Peter, as that of St. John in the keep would hardly be in need of any structural repairs at so early a date); and "of the gaol." These last doubtless stood in an outer ward added by Henry I., and at first probably only enclosed by the usual ditch and earthen rampart, furnished with stout wooden palisades. [Illustration: ST. JOHN'S CHAPEL, TOWER OF LONDON.] It is somewhat difficult to assign any precise date for the first foundation of the "Chapel of St. Peter ad Vincula apud turrim." It is not probable that it was contemporary with the Chapel of St. John, but was doubtless erected by Henry I. when he enlarged the area of the outer ward of the Tower; as this necessitated a considerable increase to the permanent garrison, St. John's Chapel in the keep would no longer suffice for their accommodation, and a new chapel would become necessary. If St. Peter's Chapel had only been parochial (which at its first erection it was not), it might have been possible to ascertain the precise date of its foundation. In 20 Henry II. (or 1174), Alnod, the engineer, received the sum of L11 13s. 4d. for works at the Tower. Other payments occur for sheet-lead for the repairs of the chapel, the carriage of planks, and timber for the kitchen,[23] the gateway of the gaol (probably Cold Harbour Gate "u"), various repairs to the "King's houses within the bailey of the Tower," and occasionally for the repairs to the "turris" or great keep itself. This, when first built, was of rough rag-stone, rudely coursed, with very open joints in thick mortar, so that these repairs (consisting, doubtless, of patching and pointing) occur with more or less frequency. Not until 1663 did the keep receive its final disfigurement, at the hands of Sir Christopher Wren, who cased part of the exterior in Portland stone, rebuilt two of the angle turrets, and "Italianised" all the window openings, thereby obliterating many valuable mediaeval details. All these outlays are certified by the view and report of two inspecting officials, Edward Blund and William Magnus, the works being carried out by Alnod, while the writs authorising payments were signed by one or other of the justiciars, Ranulph de Glanville and Richard de Lucy, or by the King himself.