Welsh (Cymraeg or y Gymraeg ( listen)) is a member of the Brittonic branch of the Celtic languages. It is spoken natively in Wales, by few in England, and in Y Wladfa (the Welsh colony in Chubut Province, Argentina). Historically, it has also been known in English as "Cambrian", "Cambric" and "Cymric".
19.0 per cent of usual residents in Wales aged three and over reported that they could speak Welsh in the United Kingdom Census 2011. According to the 2001 Census, 20.8 per cent of the population aged 3+ reported that they could speak Welsh. The Censuses suggested that there was a decrease in the number of Welsh speakers in Wales from 2001 to 2011 - from approximately 582,000 to 562,000 respectively. However, according to the Welsh Language Use Survey 2013–15, 24 per cent of people aged three and over living in Wales were able to speak Welsh, demonstrating a possible increase in the prevalence of the Welsh language since the last Census in 2011.
The Welsh Language (Wales) Measure 2011 gave the Welsh language official status in Wales, making it the only language that is de jure official in any part of the United Kingdom, with English being de facto official. The Welsh language, along with English, is also a de jure official language of the National Assembly for Wales.
The language of the Welsh arguably originated from the Britons at the end of the 6th century. Prior to this, three distinct languages were spoken by the Britons during the 5th and 6th centuries: Latin, Irish, and British. According to T. M. Charles-Edwards, the emergence of Welsh as a distinct language occurred towards the end of this period. The emergence of Welsh was not instantaneous and clearly identifiable. Instead, the shift occurred over a long period of time, with some historians claiming that it happened as late as the 9th century. Kenneth H. Jackson proposed a more general time period for the emergence, specifically after the Battle of Dyrham, a military battle between the West Saxons and the Britons in 577 AD.
Four periods are identified in the history of Welsh, with rather indistinct boundaries: Primitive Welsh, Old Welsh, Middle Welsh, and Modern Welsh. The period immediately following the language's emergence is sometimes referred to as Primitive Welsh, followed by the Old Welsh period – which is generally considered to stretch from the beginning of the 9th century to sometime during the 12th century. The Middle Welsh period is considered to have lasted from then until the 14th century, when the Modern Welsh period began, which in turn is divided into Early and Late Modern Welsh.
Welsh evolved from Common Brittonic, the Celtic language spoken by the ancient Celtic Britons. Classified as Insular Celtic, the British language probably arrived in Britain during the Bronze Age or Iron Age and was probably spoken throughout the island south of the Firth of Forth. During the Early Middle Ages the British language began to fragment due to increased dialect differentiation, thus evolving into Welsh and the other Brittonic languages. It is not clear when Welsh became distinct.