On the summit of a rising ground, by the side of a brook in the parish of Loudon in Ayrshire, stand the ruins of the ancient Castle of Loudon, which was destroyed about three hundred and fifty years ago by the clan Kennedy, headed by their chief, the Earl of Cassilis. This old Scottish stronghold was the seat of a family from which sprung Gideon Ernest Baron Loudon, or _de Laudohn_, a distinguished general of the Continental wars. Loudon of that ilk was one of the oldest families in the kingdom of Scotland. Lambin was proprietor of the lands and barony of Loudon during the reign of David I., who succeeded to the throne in 1124. James of Loudon, _dominus de eodem_, or of that ilk, obtained a charter of the same barony from Richard de Morville, Constable of the Kingdom; _Jacobo filio Lambin_, &c., also obtained a charter from William de Morville, as _Jacobo de Loudon, terrarum baroniae de Loudon_. Both these documents were granted during the reign of William the Lion, who succeeded to the throne in 1165, and are, says Sir Robert Douglas, a proof that he took his sirname from these lands, according to the custom of those early times; and his armorial bearings were, argent, three escutcheons sable. His daughter, Margaret of Loudon, was married to Sir Reginald Crawford, High Sheriff of Ayr, and became the grandmother of Sir William Wallace, the heroic defender of the liberties of his country. In later times, a branch of this old family had left "Loudon's bonnie woods and braes," so famed in Scottish song, and settled in Livonia, where their bravery and services had won them several fiefs and baronies, of which, however, they were dispossessed by Charles XI. of Sweden, after the peace of Oliva, when the Polish Republic gave up its right to the old Teutonic province. During the reign of his successor, the famous Charles XII., the Livonian nobles made a vigorous effort to regain their patrimonies and privileges; but the Swedish king having put to death their representative, the celebrated general, John Raynold Patkul, an officer in the service of Augustus, King of Poland, by cruelly breaking him alive upon the wheel, where he received sixteen blows, enduring the longest and greatest tortures that can be conceived, all hope of restoring Livonian liberty died; and with many other noble families, the Loudons dedicated themselves to the profession of arms: one became a captain in the Royal Swedish Guards, and was uncle of the subject of this memoir. GIDEON ERNEST LOUDON was born at Tootzen, in Livonia, in the year 1716.