Rothesay (Roth'say; th as in thick), a favourite Scottish watering-place, the capital of Buteshire, is beautifully situated on the north-east shore of the island of Bute, 40 miles by water W. of Glasgow and 19 SSW. of Greenock. 'sweet Rothesay Bay,' rimmed by hills 400 to 530 feet high, offers safe anchorage in any wind, and is spacious enough to contain the largest fleet. Its charming scenery, its bathing facilities, its sheltered position, and the extreme mildness of its climate have rendered Rothesay a resort alike of holiday-makers and of invalids. A score of the Clyde steamers touch regularly at Rothesay, whose commodious harbour was constructed (1822-84) at a cost of over 30,000. An esplanade was formed in 1870; and among the chief edifices are the county buildings (1832-67), public hall (1879), aquarium (1876), academy (1869), and Glenbum hydropathic (1843). The ruins of Rothesay Castle, founded about 1098, taken by Haco of Norway (1263), the death-place of Robert III. (1406), were repaired in 1871-77. Rothesay since 1398 has given the title of duke to the eldest son of the Scottish sovereign. Created a royal burgh in 1400, it returned a member from the Union till 1832. Pop. (1821) 4107; (1901)9378. See books by J. Wilson (1848) and Thorns (1870).