In
the late twelfth and early thirteenth century the invading Anglo-Normans
identified the strategic importance of the Maigue, and gradually established
a series of fortresses along its western shore, some a rebuilding of
existing forts. An early castle was built at Newtown near the mouth
of the river, another near the ford at Croom by 1215 when it was granted
to Maurice Fitzgerald, an old fort at Adare was walled, and by 1280
there was a castle on raised ground near a bridging point on the river
at Castleroberts.
There
was a castle at Fanningstown by 1285. Situated a few miles from the
bank of the river behind Castleroberts Fanningstown seems to have
been part of a second line of defence. It is difficult to date the
remaining castle ruins which consist of a small, almost square chamber
without upper floors or roof, and a round staircase tower which, pierced
with arrow-slit windows, rises about three floors, but from which
the staircase and roof have been removed.
There
is the remains of a bartizan (a turret corbelled out from the wall
on cut stone corbels, used for defence) on the west corner. This castle
was incorporated into one corner of a battlemented bawn wall which
enclosed a large courtyard.
It is
possible that the other three corners were given towers or the external
appearance of towers. There is one of the latter on the NE corner,
surmounted by double battlements which are typical of Irish medieval
castellated architecture. It could be a nineteenth-century addition,
like the one on the NE corner which was incorporated into the new
house, of which more later.

The difficulty
in dating Irish castles for which there is little documentary record
derives from the fact that architectural features are unreliable as
a source. Medieval castellated styles tended to be simple and conservative,
stone work varied little over the centuries, attacks often left the
structures badly damaged or ruined. However, the small size of Fanningstown
Castle suggests that this is the ground plan of an unimportant, probably
primarily defensive structure. In possession of the Norman Maurice
family by 1285, along with the castle at Adare, Fanningstown castle
and the cantred of which it was a part, and into which English and
Welsh settlers may well have been introduced, were an integral part
of the Norman feudal system.
A seventeenth-century
description of Fanningstown draws attention to a single plowland,
a thatched house, and an orchard. These could have sustained a steward
charged with the upkeep of the castle. They might well have lain safely
within the bawn walls, though it is not impossible that the present
extensive walled orchard adjacent to the bawn could have had a seventeenth-century
or earlier origin.
While
Fanningstown lingered as a defensive outpost Adare Castle expanded,
acquiring a massive stone keep, separate hall, stables, kitchen, dungeon,
portcullis, all of which are being currently restored. Croom Castle
too grew, becoming the principal seat of the Earl of Kildare. The
castle, renovated in the nineteenth century is still inhabited.