Steal someone’s thunder

To steal someone’s thunder means to detract from the kudos or attention due to someone by forestalling or pre-empting them. The source is John Dennis (1657-1734) an actor and minor English playwright who wrote a play called Appius and Virginia in 1709 for which he devised a new sound effect for thunder, thought to be heavy metal balls rolled against one another in a large wooden bowl. The play, which was performed at the Drury Lane Theatre in London was badly received and closed down after a short run. It was replaced by a production of Macbeth in which Dennis was astonished to hear his sound effect being used. The story goes that he jumped up and exclaimed, “They will not let my play run, yet they steal my thunder.” This, of course, was the first literal citation. It took quite some time before the figurative expression passed into the language at the end of the 19th/early 20th century, but the OED claims it was popular in theatrical circles for a long time before this.