The Visit Medway website [visit
link] tells us:
"The great keep of Rochester Castle towers over the
River Medway, dominating the skyline together with its inseparable twin, the
magnificent cathedral.
Rochester Castle is one of the best preserved and finest
examples of Norman architecture in England. Its great keep, square,
massive and one of the tallest in the country, measures 113 feet high, 70 feet
square and has walls 12 feet thick in places. It was on or close to
the present castle site that the Romans built their first fort to guard the
bridge carrying their legions over the river on their way from Dover to London
and beyond. Centuries later, in 1087, Bishop Gundulf – one of William the
Conqueror’s finest architects – began the construction of today’s castle, making
use of what remained of the original Roman city walls. The great keep was built
by William de Corbeil, Archbishop of Canterbury, to whom Henry I granted custody
of the castle in 1127.
The castle has a chequered history, having been
subjected to siege three times and in 1215 partly demolished by King John, who
gained entry by undermining the south-east tower, using the fat from 40 pigs to
set fire to the pit props. Ironclad, feature film based on this great
siege was released in 2011.
Today, visitors can see the rebuilt round tower,
contrasting with the square towers of the original Norman castle. A model
has been installed in the castle’s chapel showing how the castle would have
looked in the 14th century.
For a guided tour, an audio guide interpretation is
available at a nominal charge of £1 and is available in English, French, German
and Dutch."
The English Heritage website [visit
link] also advises:
"Strategically placed astride the London Road, guarding
an important crossing of the River Medway, this imposing fortress has a complex
history of destruction and rebuilding. Today it stands as a proud reminder of
the history of Rochester along with the cathedral and cobbled
steets.
Its Norman tower-keep of Kentish ragstone was built
about 1127 by William of Corbeil, Archbishop of Canterbury, with the
encouragement of Henry I. Consisting of three floors above a basement, it still
stands 113 feet high. Attached is a tall protruding forebuilding, with its own
set of defences to pass through before the keep itself could be entered at first
floor level.
In 1215, garrisoned by rebel barons, the castle endured
an epic siege by King John. Having first undermined the outer wall, John used
the fat of 40 pigs to fire a mine under the keep, bringing its southern corner
crashing down. Even then the defenders held on, until they were eventually
starved out after resisting for two months.
Rebuilt under Henry III and Edward I, the castle
remained as a viable fortress until the sixteenth century."
The castle is Grade I listed and the entry at the English
Heritage website [visit
link] tells us:
"Rochester Castle 7/1 (formerly listed as the Castle)
24.10.50 I GV Castle Keep, curtain walls and mural towers to bailey. A building
of exceptional significance. Built at the bridging point where Watling Street
crosses the Medway. One of the first Norman Castles to be fortified in stone.
Bailey walls, 1087-9, built by Gandulf, Bishop of Rochester for William II;
keep, 1127, built by Archbishop William of Corbeil, considerable rebuilding and
repairs throughout, 1221-32 (after the 1216 siege) and again by Edward III and
Richard II, 1367-83; some demolition and alterations, c.1872. Mainly Kentish rag
with tufa and chalk rubble. The building is described in detail by R Allen Brown
(1986) which should be consulted for further information. Gandulf's curtain wall
survives to the W(Mersey side) and incorporates remains of the Roman city wall
(see Refs 7/2 and 9/2); strengthened in C13. SE section, including the drum
tower, mid-C13; E section (C14) includes 2 curtain walls, one of which (now a
cottage) contains vaulted room, spiral stone stair and 2 garderobes. N section
of wall, fragmentary, is incorporated into the garden walls to the rear of High
Street properties. The N perimeter wall of the present castle precinct is marked
by a C20 wall with palings. To the NW, the bastion (1378-83), altered and
breached by a prominent Norman-Revival round-headed arched entrance of c1872.
Keep, roofless and without principal floors, rectangular on plan with corner
turret (that to SE in circular form, Mid C13) and contempotary forebuilding
(with chapel and chambers) to N reached from W at 1st floor level. Main building
consists of ground-floor basement; 1st floor apartments; great hall and chamber
occupying 2 storeys; private apartments above, all divided by massive cross wall
pierced by doorways and (at great hall level) a 4-bay arcade. It contains a well
shaft. NE stair to all floors; SW stair excludes access to basement. Decoration
sparingly applied: externally to principal doorways and upper floor embrasures;
internally mainly chevron with some shafting; arcade with scalloped capitals.
Scheduled Ancient Monument."