Complex sentence: Pietro Perugino was born Pietro Vannucci in Città della Pieve, Umbria, the son of Cristoforo Marie Vannucci; his nickname characterizes him as from Perugia, the chief city of Umbria.
Split into simpler sentences: Pietro Perugino was born Pietro Vannucci in Città della Pieve, Umbria, the son of Cristoforo Marie Vannucci. Pietro's nickname characterizes him as from Perugia, the chief city of Umbria.