The most famous Norman great tower today is the White Tower of London (Figure 8). The castle was begun in the 1070s and construction continued into the 1090s. To improve his original ditch and bank de fenses in London, William the Conqueror put Bishop Gundolph of Rochester in charge of the building project. The building we see today is twelfth century and later. (A study of the wood gives a date in the early twelfth century for the upper part of the tower.) The kings lavished money on the castle in 1129–30, 1171–72, and the 1180s and recorded the annual expenses in official royal accounts (known as Pipe Rolls). In 1190 Richard the Lion Hearted spent enormous sums on a new ditch, bank, and curtain wall. Today the castle has been heavily restored and is entirely surrounded by later buildings, but it still exerts a sense of grim strength. With plastered and whitewashed walls, the White Tower lived up to its name. Since it stood beside the river Thames, not on a hill or motte, its lower walls had to be very thick, between fourteen and fifteen feet thick at the base. The tower had a rectangular plan, 97 feet by 118 feet. Four pilaster buttresses (projecting masonry panels) enriched each outer wall, dividing the walls into bays (compartments or units of space), and corner buttresses extended upward to form turrets at the corners. The windows have been enlarged, and a top story added. The forebuilding that once held the stair has been destroyed and replaced today with wooden stairs. The tower had only this one entrance, so everyone and everything—even supplies going to the basement—came through this door. Since there are few accommodations for a household, the White Tower may have been designed as a public and administrative building rather than as a residence. It has two levels of state rooms. A wall pierced with wide arches divides each floor into two halls of unequal size. Spiral stairs join the floors, and in one corner an unusually wide stair must have been used for formal processional entrances. A chapel dedicated to St. John replaces one corner turret. Its apse forms a semicircular tower (Figure 9). Romanesque in style and construction, the chapel’s cylindrical columns divide the space into a nave and aisles and support a barrel vault. The groin-vaulted aisles support galleries, which join a wall passage running all the way around the tower at the upper window level. On the upper floor the rooms are luxurious, with large windows, fireplaces, and garderobes.