The development of a new town centre expansion zone immediately to the west of the existing town centre (at Townparks, Market Street and Emmet Street) is due to begin early in 2007. This will comprise open civic spaces, retail and office space, residential developments and a new headquarters for the Office of Public Works, which is due to decentralise to the town by 2009.
The town is home to Western Europe's largest Norman castle, Trim Castle (or King John's Castle) which was built in the late 12th century following the Norman invasion of Ireland's eastern seaboard. Trim and the surrounding lands were granted to Hugh de Lacy, a Norman knight. Richard II of England stayed there before being ousted from power 1412. Once a candidate to be the country's capital, the town has also occupied a role as one of the outposts of the Pale. It was also designated by Elizabeth I of England as the planned location for a Protestant Dublin University (known as Trinity College, Dublin). However this was revised by Sir Francis Drake, who advocated the case for locating the University in Dublin. In 1649 after the sacking of Drogheda, the garrison of Trim fled to join other Irish forces and the town was occupied by the army of Oliver Cromwell. There were many local disturbances in neighbouring villages in the Irish Rebellion of 1798, most infamously the massacre on the Hill of Tara, following the dispersal of the Wexford rebellion. Trim was represented by Arthur Wellesley in the Irish Parliament from 1790 to 1797.
The 19th century saw the construction of Trim Courthouse, St. Loman's Catholic church, St. Patrick's Anglican church, the Wellington column, the current Bank of Ireland building, and Castle Street by Lord Dunsany, a major landowner. Following the Great Irish Famine of 1846-1849, the practices of agriculture in the hinterland altered, with a change in emphasis from tillage to stock raising. This resulted in a change in the business life of Trim. Trim developed as a market town for the productive agricultural hinterland. Some small scale local industries were developed including envelope, and leather product manufacturing. Trim was also chosen as location for the Timoney Engineering company to make Fire Tenders. However in the main the town continued to mainly be a service centre for its immediate area. Trim was the birth place of the mother of prominent Irish nationalist, Pádraig Mac Piarais. During the Irish War of Independence, local companies of the Irish Republican Army took Trim RIC Barracks, a large structure located on the current site of the Castle Arch Hotel, secured the arms from the barracks and then burnt down the Barracks (1920). A large part of the town was burned as a reprisal by the British Crown forces.
A new bridge was built on the Boyne in the 1980s to divert heavy traffic from the town. This was then enhanced by the construction, in a series of stages, of an inner relief road, which now makes it possible for heavy traffic to achieve a complete by-pass of the town. The Watergate bridge was replaced in 2005. The local town council purchased a field beside the new bridge in 2004, as it was expected to be of archaeological significance.
As part of the Civil Service decentralization plan of the Irish government, Trim was chosen as the location of the headquarters for the state body known as the Office of Public Works. The movement of this state administration function to Trim resulted in Trim being the first location outside of Dublin, to complete a satisfactory decentralization move. Trim has seen some growth in recent years with growth as a tourist and business centre.
Since 1995 the RTÉ Radio 1 longwave transmitter at Clarkestown, some 11 km southeast of Trim, has broadcast the AM version of Radio 1 (sometimes known as RTÉ Europe) on 252 kHz (1190.4 m) at a power of 1.5 MW. Prior to this date, RTÉ's main AM transmission centre had been near Athlone.
Trim was also the setting for the first full-length Irish martial arts movie Fatal Deviation. (A low-budget production from 1998 that tells the story of a young man trying to rebuild his life after returning from reform school only to be harassed by a gang of local drug dealers.)
Famous old poem about Trim "The town of Trim is dark and dim and in it lies a Steeple. At every door there stands a whore to mock the daecent people." Author unknown.
Trim GAA Club have won the Meath Senior Football Championship on one occasion, in 1962. Trim is one of the two most successful teams (the other being Kilmessan) in the Meath Senior Hurling Championship, with both clubs between them winning almost half the championships played.
Trim Flying Club (EITM) operating from Trim Airfield, Trim Co.Meath Ireland is a voluntary flying organisation, situated in the heart of the Boyne valley of Meath, located in the North-East of the country only 15 minutes flying time from the coast and 15 minutes from Dublin Airport (EIDW). The club is run by a committee, appointed in accordance with the Memorandum and Articles of Association of Trim Flying Club Ltd., which meets monthly to conduct the business of the Club. Trim Flying Club is a Registered Training Facility (RTF). The airfield has one runway, 28/10 which is 560 meters long. The field is easily recognisably from the air. Simply fly towards Trim town and look to the north east of it. A bright yellow barn located beside the airfield is clearly visible for miles around. As well as Trim Flying Clubs' aircraft, the airfield is also home to many other aircraft including microlights.