 In 1450, the castle was bestowed by James II upon Sir George Crichton, Lord High Admiral of Scotland, who was briefly created Earl of Caithness in 1452.In 1455, the earldom and castle were granted by James II to William Sinclair, Baron of Roslin and Lord Chancellor of Scotland.The castle passed to the Sinclairs of Ulbster, a branch of the Sinclair Earls of Caithness, in the 18th century.