After Hugh de Grentmesnil’s death, the castle was passed
into a succession of mediaeval magnates including both Simons de Montfort,
father and son, in the thirteenth century, and John of Gaunt in the fifteenth
century. Hugh’s heirs held various titles; the earliest were simply Earl of
Leicester, subsequently they acquired the principal title of Earl of Lancaster.
In the fourteenth century they became Dukes of Lancaster. Many of these
magnates set about remodelling the castle for their own purposes. At first the
main purpose of the remodelling was the improvement of the defensives. But as
the threat of the locals rising in revolt receded, the castle gradually became
less of a fortification and more of the comfortable residence of powerful
aristocrats.
In the early-mid twelfth century, quite early on in the
development, Robert de Beaumont, second Earl of Leicester, set about rebuilding
the timber castle in stone. This included the replacement of the wooden
palisades with stone walls built into the outer face of the ramparts, and the
replacement of the church and hall with stone buildings on similar sites. The
first stone Church of St Mary de Castro was considerably smaller than the
present building. This early Norman church was very richly decorated. Some of
the exterior detail of this building can still be seen as interior features.
The twelfth century Great Hall forms the core of the present castle hall. In
addition to stone walls it had a roof supported on two lines of large timber
posts. These posts divided the hall into three; the main body of the hall
running north to south, with two flanking aisles east and west. Some of the
original stonework and fragments of the timber posts can still be seen in the
interior of the present building. Unfortunately because the top of the motte
was modified in the nineteenth century it is not possible to say for certain
whether the original timber keep was replaced by a stone keep.
As the castle became more of a comfortable residence
additional suites of rooms were added to the great hall, both to provide
private accommodation for the Earl’s family and a service wing. All surface
traces of these later mediaeval wings have been removed, but a large
stone-lined storage basement, known as John of Gaunt’s Cellar, survives below
ground to the south of the hall.
