A lady of considerable fortune in London. Her maiden name was Robinson, and she is nearly related to doctor Richard Robinson, lord Rokeby, archbishop of Armagh, and lord primate of all Ireland. Her supposed heir is Mathew Mortagu esquire, who was elected into parliament for Boffiney in Cornwall at the last general election. She published in 1769 an Essay on the Writings and Genius of Shakespear, chiefly in reply to the animadversions of Mr. de Voltaire, in one volume octavo. This work, though inferior in merit to the dignity of its subject, has been uniformly celebrated with the loudest applause. A circumstance, which has probably conduced to its reputation, is that of Mrs. Montagu's keeping open house for the regale of the English literati.