Claudio Giovanni Antonio Monteverdi was born in Italy and worked in one of the major cathedrals in Venice, composing music and teaching and performing. Much of his work has been lost. He was one of the first people to write an opera.
He is particularly famous for:
9 books of madrigals
What is a madrigal?
What is an opera?
How does Monteverdi’s style sound different from Renaissance composers such as Palestrina and Lassus?
Does that tell you anything about why he wrote operas?