In Roman times farmsteads existed on the site of Barry Castle and Biglis and there were verbal reports of discovery of a cemetery including lead coffins with scallop-shell decoration. Both St. Baruc's Chapel and St. Nicholas Church have re-used Roman bricks and tiles incorpoarated in their building fabric and a Roman villa was discovered in Llandough. In 1980 a Roman building consisting of 22 rooms and cellars in four ranges around a central courtyard was excavated at Glan-y-môr and is believed to be a third century building associated with naval activity, maybe a supply depot.
The Vikings launched raids in the area and Barry Island was known to be a raider base in 1087. Flat Holm and Steep Holm islands in the Bristol Channel have their name Holm name derived from a Scandinavian word for an island in an estuary. The excavation of the Glan-y-môr site revealed the site had been reused in the 6th and 7th century and also between AD 830 and 950 as a dry stone sub-rectangular building with a turf or thatched roof.
By 1871 the population of Barry was over the 100 mark there being 21 buildings, the new estate-owning Romilly family being involved in the build up of the village but it remained a largely agricultural community. It grew when it was developed as a coal port in the 1880s. The coal trade was growing faster than the facilities at Cardiff in Tiger Bay ever could and so a group of colliery owners formed the Barry Railway Company and chose to build the docks at Barry. Work commenced in 1884 and the first dock basin was opened in 1889 to be followed by two other docks and extensive port installations. The Barry Railway brought coal down from the South Wales Valleys to the new docks whose trade grew from one million tons in the first year, to over nine million tons by 1903. The port was crowded with ships and had flourishing ship repair yards, cold stores, flour mills and an ice factory. By 1913, Barry was the largest coal exporting port in the world.
Behind the docks rose the terraced houses of Barry which, with Cadoxton, soon formed a sizeable town. The railways which had played a major part in the development of the dock did a great deal, too, to make Barry Island a popular resort.
Following the rise of diesel and electric power on the UK's railways, the marshalling yards at Barry Docks became the largest repository of steam engines awaiting scrapping in the UK. Eventually a significant proportion of the engines were saved by rail preservation organisations, although many were vandalised or looted by souvenir hunters.
During its industrial peak a number of ships sunk off the Barry coast.
The road from Bonvilston was originally the B4266, as only Pontypridd Road within the town still is, and the road from Highlight Park right through the Vale to Bridgend was the B4265, as beyond the airport it still is. Since the 1970s, parts of these roads are numbered A4226, with the result that the A4226 radiates from Weycock Cross roundabout in three directions.
Although still a port, Barry is more important now as a manufacturing town and as a service centre for the Vale of Glamorgan. Barry Docks and the adjoining industrial area form the largest employment centre in the town. The docks, whose road links were dramatically improved with the opening of the Docks Link Road in 1981, now have direct road access with the M4 motorway. The docks can handle vessels up to 23,000 tons and the first-class tidal position close to the deep-water channel of the Severn Estuary, allows for regular scheduled sailings. With its extensive transit sheds, warehouses and open storage, the docks are well equipped to handle bulk cargoes for which the batteries of high capacity grab cranes are invaluable. Two roll on/roll off berths are available and have been extensively used by routes to Ireland and West Africa. These and the other port facilities have seen an increasing variety of traffic in recent years. The town is famous for its working class roots and background and has a thriving town council which is controlled by the Labour Party.
The great majority of industrial firms are located in the dock area. By far the largest are the chemical producing concerns such as Cabot Carbon and Dow Corning who have just completed the development of the largest silicones plant in Europe. Other main employers in Barry Docks are Jewson Builders' Merchants, Western Welding and Engineering, Bumnelly, Rank Hovis and, of course, Associated British Ports Holdings who, since 1982 have run the docks as successors of the British Transport Docks Board.
To the west of Barry is Porthkerry Park. This is a large area of open space, with woodlands, streams, a few modern attractions and access to a pebbly beach. In the park is the Barry Railway Company viaduct with 13 arched spans standing 110 ft high. The Barry Railway reopened in September 2006 and provides a scenic view and link to towns such as Llantwit Major.
The Barry Island peninsula was an island until the 1880s when it was linked to the mainland as the town of Barry expanded. This was partly due to the opening of Barry Dock by the Barry Railway Company. Established by David Davies, the docks now link up the gap which used to form Barry Island.
On Barry Docks, the original dock offices are now used by the county council. The dock offices themselves are one of just a handful of buildings in the world classed as calendar buildings. The dock offices has four grand fire places and clocks on its roof, to represent the four seasons, 52 rooms for every week of the year and a grand 365 windows.
There is a railway station still to access the island at Barry Docks, there is also a heritage railway station which still homes original refurbished steam passenger trains. The railway is always open to the public and annually holds events involving a large steam engine replica of Thomas the Tank Engine.
Barry Island is now known for its beach and Barry Island Pleasure Park. From 1966, the island was home to a Butlins Holiday camp, which was closed in 1987 and taken over by Majestic Holidays who renamed it Barry Island Resort. Between Butlins' closure and Majestic's reopening the camp was used as for filming scenes in the "Shangri-La" holiday camp from the Doctor Who serial Delta and the Bannermen. The camp closed in 1996 after Majestic had a disagreement with the local council, who refused an entertainments licence unless work was carried out to improve the now 30-year-old site. It was redeveloped for housing between 1997–2003 with the remaining two camp buildings and outdoor pool demolished in early 2005.
The railway station is the home of both the national services of Arriva Trains Wales, as well as the preserved Vale of Glamorgan Railway. From the late 1960s onwards, Woodhams Yard, Barry was home to hundreds of British Rail steam locomotives that were due to be scrapped. Many were sold to preservation societies. By the late 1980s, two thirds had been saved for preservation.
From the 1536 Act of Union, Glamorgan was represented in parliament by one member, elected by the freeholders in the county. In 1885, the constituency was split into three with the creation of East Glamorganshire, Mid Glamorganshire and South Glamorganshire. The Representation of the People Act 1918 created the Llandaff and Barry constituency. Sir William Cope (Conservative) won the 1918 general election. Labour regained the seat at the 1929 general election when Charles Ellis Lloyd was returned but two years later lost the seat to the Conservatives' Patrick Munro.
After Munro's death in 1942 Cyril Lakin, a farmer of the local Highlight Farm won the by-election for the Conservatives. Arwyn Lynn Ungoed-Thomas (Labour) won the seat at the 1945 general election. The Llandaff and Barry constituency was abolished by the Representation of the People Act 1948. and replaced by the Barry parliamentary constituency. This seat was first contested in the United Kingdom general election, 1950 when Dorothy Rees (Labour) was elected. She lost the seat to Sir Herbert Raymond Gower (Conservative) at the 1951 general election. He held the seat until its abolition in 1983.
It was replaced by the Vale of Glamorgan constituency which Sir Herbert Raymond Gower (Conservative) won at the 1983 general election. He remained as MP until his death in 1989. At the subsequent by-election the seat was won by John Smith (Labour). At the 1992 general election Walter Sweeney (Conservative) won it by only 19 votes. That made it the most marginal seat in Britain. John Smith won it back at the 1997 general election and has remained MP to date.
Barry is part of the Vale of Glamorgan Assembly constituency and part of the South Wales Central Assembly region. Jane Hutt has been the Vale of Glamorgan Assembly member since the inception of the Welsh Assembly.
The local council, Barry Town Council, is the largest town council in Wales. Recently it has given Olympic Silver Medalist David Davies freedom of the town. The first freedom granted since 1958. The current mayor is Stuart Egan who represents Butrills Ward. The town council is controlled by Labour.
The current local unitary authority, created in 1995, is the Vale of Glamorgan Council which has its administrative headquarters in Barry. There are 23 wards electing 47 councillors which comprise Baruc (Barry) (2 councillors), Buttrills (Barry) (2), Cadoc (Barry) (3), Castleland (Barry) (2), Court (Barry) (2), Gibbonsdown (Barry) (2), Dyfan (Barry) (2), Illtyd (Barry) (3), Cowbridge (3), Dinas Powys (4), Llandough (Penarth) (1), Llandow Ewenny (1), Llantwit Major (4), Cornerswell (Penarth) (2), Plymouth (Penarth) (2), Stanwell (Penarth) (2), St. Augustines (Penarth) (2), Peterston-super-Ely (1), Rhoose (2), St Athan (1), St Brides Major (1), Sully (2), Wenvoe (1).
The main forms of public transport in the town are bus and rail. Barry is served by Cardiff Bus which operates services to Llantwit Major, Penarth, Cardiff International Airport and Cardiff City Centre as well as operating town circular services. Barry's King's Square bus station is located on King's Square in the town centre. The A4050 road connects Barry to Cardiff.
There are 4 railway stations in the town: Barry, Barry Docks, Barry Island and Cadoxton. These are operated and served by Arriva Trains Wales and are on the Cardiff Urban Area rail network. Frequent services operate to Bridgend via Llantwit Major and Rhoose Cardiff International Airport, and to Cardiff Queen Street via Dinas Powys, Cardiff Grangetown and Cardiff Central. The latter service can continue to either Merthyr Tydfil, Pontypridd and/or Aberdare.
Barry is located less than 3 miles (4 kilometres) east of Cardiff International Airport.