In the 16th century, "haste, post, haste" was used to inform "posts," as couriers were then called, that a letter was urgent and must be hastily delivered. Posts would then speedily gallop along a route with a series of places at which to get a fresh horse or to relay the letter to a fresh messenger. Shakespeare was one of the first to use a version of the phrase adverbially in Richard II. "Old John of Gaunt . . . hath sent post haste / To entreat your Majesty to visit him," the Bard versified. He also used the phrase as an adjective in Othello (a use that is now obsolete): "The Duke . . . requires your haste-post-haste appearance," Lieutenant Cassio reports to the play's namesake.