South Glamorgan in the context of "Monmouthshire (historic)"

Cardiff (/ˈkɑːrdɪf/ ; Welsh: Caerdydd [kairˈdiːð, kaːɨrˈdɨːð] ) is the capital and largest city of Wales. Cardiff had a population of 383,919 in 2024 and forms a principal area officially known as the City and County of Cardiff (Welsh: Dinas a Sir Caerdydd). The city is the eleventh largest in the United Kingdom. Located in the southeast of Wales and in the Cardiff Capital Region, Cardiff is the county town of the historic county of Glamorgan and in 1974–1996 of South Glamorgan. It belongs to the Eurocities network of the largest European cities. A small town until the early 19th century, its prominence as a port for coal when mining began in the region helped its expansion. In 1905, it was ranked as a city and in 1955 proclaimed capital of Wales. The Cardiff urban area covers a larger area outside the county boundary, including the towns of Dinas Powys and Penarth.

Cardiff is the main commercial centre of Wales as well as the base for the Senedd, the Welsh Parliament. At the 2021 census, the unitary authority area population was put at 362,400. The population of the wider urban area in 2011 was 479,000. In 2011, it ranked sixth in the world in a National Geographic magazine list of alternative tourist destinations. It is the most popular destination in Wales with 21.3 million visitors in 2017. It was voted as the best city in the UK at the 2023 Readers' Choice Awards.

The Cardiff accent, also known as Cardiff English, is the regional accent of English, and a variety of Welsh English, as spoken in and around the city of Cardiff, and is somewhat distinctive in Wales, compared with other Welsh accents. Its pitch is described as somewhat lower than that of Received Pronunciation, whereas its intonation is closer to dialects of England rather than Wales.

It is estimated that around 500,000 people speak Cardiff English. The accent is generally limited to inside the city's northern boundary, rather than the nearby South Wales Valleys where the spoken variety of English is different. However, the accent area spreads east and west of the city's political borders, covering much of the former counties of South Glamorgan (Barry) and south-west Gwent, including Newport and coastal Monmouthshire.

South East Wales is a loosely defined region of Wales generally corresponding to the preserved counties of Mid Glamorgan, South Glamorgan and Gwent. Highly urbanised, it includes the cities of Cardiff and Newport as well as large towns in the South Wales Valleys.