It was created on 25 April 1700 for John Johnstone, one of the Scottish representatives to the 1st Parliament of Great Britain, with remainder to his heirs male.
His only child, Laura, inherited the Pulteney estates and was created Countess of Bath in 1803 (see this title for more information).
George Johnstone, fourth son of the third Baronet, was an officer of the Royal Navy, a Member of Parliament, and the first Governor of West Florida.
Richard Vanden-Bempde-Johnstone, eldest son of Colonel John Johnstone, second son of the second Baronet, was created a baronet in 1795, with remainder to his younger brother, who was the grandfather of Harcourt Vanden-Bempde-Johnstone, 1st Baron Derwent (see the Baron Derwent for more information on this branch of the family).
See also Rothschild, Emma: "The Inner Life of Empires" Princeton 2011, which is based on an eighteenth-century Johnstone family letterbook, held by Edinburgh University.