https://www.gramophone.co.uk/musicians/artist/arturo-toscanini-47225

Perhaps the most internationally famous conductor ever, Toscanini rose to instant stardom when he put down his cello and jumped up to the podium to fill in for the conductor during a performance of Verdi’s opera Aida. It was 1886; he was 19, and it was the first time he’d ever conducted.

The last time he’d conduct a live performance was in 1954, 68 years later. By then, he was the first conductor to have appeared regularly on television, and was certainly considered the first true media star of the conducting world.
http://www.npr.org/templates/story/story.php?storyId=89059352