When, therefore, the Norman nave, as originally designed, was approaching completion, the designers determined upon an extension of the nave, and a much grander western finish to the church than had before been contemplated.  This idea included a dignified western transept, the dimensions of which, from north to south, should exceed the entire width of the nave and aisles.  This would of necessity involve the lengthening of the nave, because the monastic buildings came close to the south aisle of the nave, at the point where the original termination of the church was to have been, as may be seen by the old western wall of the cloister, which is still standing.

The two next abbots were Andrew (1193-1200), and Acharius (1200-1210).  To one or both of these may be assigned the western transept.  By their time the Norman style was giving place to the lighter and more elegant architecture of the Early English period, the round arch was beginning to be superseded by the pointed arch, and the massive ornamentation which marks the earlier style was displaced by the conventional foliage that soon came to be very generally employed.  Most wisely, however, the Peterborough builders made their work at the west end of the nave intentionally uniform with what was already built.  Very numerous indications of this can be seen by careful observers.  The bases of the western pillars, the change in the depth of the mouldings, characteristic changes in the capitals in the triforium range, and especially the grand arches below the transept towers, which are pointed, but enriched with ornamentation of pronounced Norman character, all point to the later date of this western transept.

At the west wall of the church all trace of Norman work disappears.  The arcade near the ground, the large round arch above the door, the great west window and its adjacent arches (not, of course, including the late tracery), are all of distinct Early English character.  The whole of this wall may be held to be an integral part of the west front, and not of the transept which it bounds.

When we come to the most distinctive feature of the cathedral, the glorious west front, we find we have no help whatever from the chronicles.  Nowhere is there the smallest reference to its building.  Other works raised by the Abbots of the period are named, but the noble western portico is never once mentioned.  Perhaps the rapid succession of abbots after Acharius may account for this.  The building must have taken some years, and the credit of the whole cannot be given to one.  There were four Abbots after Acharius before the church was dedicated.  They were Robert of Lindsey (1214-1222), Alexander (1222-1226), Martin of Ramsey (1226-1233), and Walter of S. Edmunds (1233-1245).  During the abbacy of this last the church was dedicated on the 4th of October 1237, (according to the Chronicon Angliae Petriburgense), or on the 28th of September 1238, according to Matthew Paris.  The Bishop of Lincoln,