Anglesey, a county in North Wales, comprehending the island of that name. It is divided from the main island of Great Britain by the narrow river, or rather armlet of the sea, called the Straits of Menai. Over this water a most magnificent suspension bridge has been recently completed, which affords a great facility to the intercourse between London and Dublin. The extent of the county is about 271 square miles, or 174,000 acres. The soil is but moderately fertile; but in average years it yields more barley and oats than the consumption requires. The surplus generally finds a vent in Liverpool. A number of horned cattle, sheep, and hogs, are annually sent over the Menai. The most valuable product of the island arises from the mines. The chief of these, the Parys mine, is the most abundant in copper ore of any mine known in the world; and even in the water lodged beneath the bed of ore, quantities of nearly pure copper are obtained by exposing it to iron. A mine of lead, but rich in silver, has been discovered near the same mountain. Quarries of various kinds of marble, and mines of asbestos, are also found on the island. Coal is obtained at Maltreath in considerable quantities. The mines have, however, of late years diminished in productiveness, especially those of copper. The herring fishery is a branch of industry which in some years gives employment to a portion of the inhabitants.

The island has been celebrated in the most remote periods as the seat of the druidical pontiff, and the great nursery of the instructors in that kind of religion or superstition, of which but little has been handed down by any other mode than by tradition, and which is attended with the doubts and uncertainty naturally arising from that mode of communication. See the article Druid.

At present the Welsh language, of the northern dialect, is almost the exclusive language of the peasantry; but in the towns, especially at Holyhead, English is very generally understood. The county contains 5 towns and 67 parishes. The number of inhabitants in 1801 was 35,000; in 1811, 38,300; and in 1821, 46,000. The county returns one member to parliament, and one is also returned by the borough of Beaumaris. The towns with their population, are, Holyhead, 4071; Amlwch, 5292; Aberffraw, 1204; Beaumaris, 2205.