Caernarfonshire. County of north Wales. It was part of the tribal territory of the Celtic Venedotae, later the Welsh kingdom of Gwynedd. ‘Arfon’ is the land over against Môn (Anglesey) and the county's name is derived from the Roman fortress Castrum (or Caer) of Segontium—Caer yn Arfon. With the destruction of Gwynedd by Edward I, Arfon, together with the Llŷn peninsula, Eifionydd to the south, and Arllechwedd, the land west of the Conwy river, were joined together by the statute of Rhuddlan in 1284 as Caernarfonshire, a county of the principality of Wales. At the Act of Union with England in 1536 the county remained, but in 1974 became part of the county of Gwynedd and was divided into three districts, Arfon, Dwyfor (Llŷn), and Aberconwy. In 1996 Môn was detached and Caernarfonshire, Eifionydd, and Aberconwy remain as the new county of Gwynedd.

The county was dominated by the Snowdon massif (Eryri) with the highest peaks in Wales (yr Wyddfa, 3,560 feet), a glaciated terrain of steep mountain slopes, deeply eroded valleys, and lakes. It is one of Wales's national parks. It is predominantly agricultural with sheep-farming as the main enterprise but extensive slate-quarrying and mining in the 18th and 19th cents. have scarred the landscape. There is still some slate production, but tourism, particularly hill-walking and rock-climbing, is a significant element in the economy. Hydroelectric schemes exploit the steep slopes and fast-flowing rivers.

Regarded as the primary mountain fastness of Wales, it has retained Welsh speech. In 1901, 89.6 per cent spoke Welsh with 47.7 being monoglot Welsh. By 1991 the percentage speaking Welsh had fallen to 61.5. In 1991 the total population was 133,338.

Harold Carter