Antonio Vivaldi was an Italian composer who lived from 1678-1741 in the Baroque era. Taught by his father, he was an extraordinary violinist.

Throughout most of his (working) life, he was employed by Ospedale della Pietà, which was an orphanage-like home for daughters of noblemen, where he chiefly taught violin. The musical standards of this Ospedale della Pietà were among the highest in Venice at the time.

Vivaldi was said to have written over 90 operas, but less than 50 exist today. His first opera was Ottone in villa (which was produced in Vicenze in 1713).

Vivaldi also wrote many concerti for solo instruments, one of the more famous being the Four Seasons for violin.

Click here to see the stats of Vivaldi's musical works.

A few excellent sites to visit:
antonio-vivaldi.org
Classical Music Archives
Classical.net