In 1784 Piccinni became professor at the Royal School of Music, a school which later became part of the Conservatoire. When the French Revolution broke out in 1789, Piccinni returned to Naples. At first he was warmly welcomed by King Ferdinand IV; but when his daughter married a French democrat the Neapolitans were angry. They said he was a revolutionist. He was not allowed to leave his house for four years.