In St. Albans this plan was further developed; from each arm of the transept two apses projected eastward, the outer ones consisting only of a semicircular projection from the transept, the inner ones of a rectangular bay from which the semicircular part ran eastward. The choir aisles, as we should now call them, consisted of four bays, beyond which they ended in a projection semicircular within, but rectangular when seen from the outside, the walls being thickened at the corners. These aisles were divided from the presbytery not by open arcading but by solid walls. The presbytery itself terminated in a semicircle projecting beyond the ends of the aisles. This extended as far as the centre of the present retro-choir.
Above the crossing rose the central tower, much as we see it to-day, save that it was probably crowned with a pyramidal cap rising from its outside walls. Probably also the tower as well as the rest of the church was covered with whitewashed plaster, thus hiding the material of which it was built—the Roman bricks of which mention has been already made. These bricks surpass in hardness and durability those of modern days, and are of different size and shape from those we are acquainted with. Those used in St. Albans are of two sizes, 17 × 8 × 2 and 11 × 5½ × 2. The joints are wide, the mortar between the courses being almost as thick as the bricks. The window jambs and the piers were built or faced with brick; even the staircases were of brick. What stone was used is clunch, from Tottenhoe in Bedfordshire, which, according to Lord Grimthorpe, is admirably suited for interior work, but absolutely worthless for exterior, as it decays very soon, and if it gets damp is shivered into powder by frost.
The Norman church, finished as we have seen in 1088, stood without change for rather more than a century. Then changes began. Abbot John de Cella (1195-1214) pulled down the west front and began to build a new one in its place. He laid the foundation of the whole front, but then went on with the north side first. The north porch was nearly finished in his time; the central porch was carried up as far as the spring of the arch; the southern porch was carried hardly any way up from the foundations.[5] The porches are described by those who saw them before Lord Grimthorpe swept away the whole west front as some of the choicest specimens of thirteenth-century work in England. The mouldings were of great delicacy, and were enriched with dog-tooth ornament. It is said that Abbot John was not a good man of business, and that he was sorely robbed and cheated by his builders, and so had not money enough to finish the work that he had planned. To his successor, William of Trumpington, it therefore fell to carry on the work. He was a man of a more practical character, though not equal to his predecessor in matters of taste. He finished the main part of the western front. Oddly enough no dog-tooth ornament was used in the central and southern porches, and the character of the carved foliage differs also from that of the north porch. In Abbot John's undoubted work the curling leaves overlap, and have strongly defined stems resembling the foliage of Lincoln choir, while that of Abbot William's time had the ordinary character of the Early English style. There is evidence to show that he intended to vault the church with a stone roof; this may be seen from the marble vaulting shafts on the north side of the nave between the arches of the main arcade, which, however, are not carried higher than the string-course below the triforium. The idea of a stone vault was, however, abandoned before the two eastern Early English bays on the south side were built, for no preparation for vaulting shafts exists there.
Abbot John de Cella had begun to build afresh the western towers, or, according to some authorities, to build the first western towers that the church ever had; we have no record of their completion, and it is said that Abbot William abandoned the idea. We have only the foundations by which we can determine their size. William of Trumpington transformed the windows of the aisles into Early English ones. He also added a wooden lantern to the tower, somewhat in the style of the wooden octagon on the central tower of Ely.
At some time, but we do not know exactly when, the Church or Chapel of St. Andrew adjoining the north nave aisle of the monks' church, extending as far east as the sixth bay, was built for the use of the parishioners, who had no right to enter the monastic church. This Church of St. Andrew opened into the north aisle of the Abbey Church, being separated from it by an arcade of four arches. It had a nave with aisle and chancel. Its total length was about 140 feet, its width about 61 feet. It is conjectured that the north-western tower was converted into a kind of antechapel or entrance porch for the Church of St. Andrew. There was a door leading from the aisle of the Abbey Church into the chancel of St. Andrew's; this door, walled up, may still be seen in the fifth bay from the west end. In order to avoid the necessity of returning again to the history of this church, it may here be stated that it was rebuilt by John Wheathampstead after he had been re-elected to the office of Abbot in 1451; and that it was destroyed after the dissolution of the monastery, when there was no longer any need for it, as the parishioners bought the Abbey Church for parochial use. The place of the old arcading was then taken by a blank wall without any windows; this was pulled down and the present wall built by Lord Grimthorpe.
In the latter half of the thirteenth century the reconstruction of the eastern end was begun by Abbot John of Hertford. Here, as in many other churches, the Norman choir was too short for thirteenth-century requirements. The walls of the presbytery were raised and its high-pitched roof converted into a flat one. The church was gradually extended eastward by Abbots Roger of Norton and John of Berkhampstead; first the Saint's Chapel was built, then the retro-choir, and finally the Lady Chapel, which was finished by Abbot Hugh of Eversden in 1326.
Another change was necessitated by an event which took place on St. Paulinus' Day, October 10th, of the year 1323. For on that day a calamity such as had never before happened befell the church. The celebration of Mass at an altar of the Blessed Virgin was just over, a great multitude of people, men and women, still being in the church, when two of the Norman piers of the main arcade on the south side fell outwards one after the other with a great crash, and about the space of an hour afterwards the wooden roof of the nave which had been supported by these columns also fell; the piers themselves had crushed the south wall of the aisle and the cloisters, so that a complete wreck was made of the south-eastern part of the church westward of the tower. But this disaster was accompanied by a great marvel, for though many persons were standing close by, not one was injured; and a still more wonderful thing is recorded: the monk whose duty it was to guard the shrine of St. Amphibalus, which at that time stood in the nave, had been celebrating at the altar—he had finished even to the washing of the sacred vessels—when he saw the columns fall; he withdrew a little from the altar and received no harm. Some of the wreckage fell on the shrine of St. Amphibalus, and though the marble pillars supporting the canopy were broken, yet the chest which contained his relics suffered no harm. This wonderful preservation of life and limb and shrine was naturally attributed to the intervention of the blessed martyr St. Amphibalus.