In 1718 Vivaldi left Venice and moved to Mantua, where he became the director of music for the governor, Prince Philip of Hesse-Darmstadt. He composed his famous "Four Seasons" as well as several operas during this time. He went to Rome in about 1721, where he performed on several occasions for the Pope. While he was travelling, he continued to write music for the girls at the Pietà, over the years he sent them about 140 concertos. He went to a number of cities in Europe to have his operas performed including Vienna, Verona, and Prague. He often went back to Venice to rehearse his music with the girls.