Great actor. The part was pure slander, though. What's more, it's based on actual slander during Salieri's lifetime, which contributed to his nervous breakdowns later in life. Despite the rumors, there is absolutely no evidence Mozart was poisoned. The sad fact is that many young people died of disease in that day and age, and Mozart was one of those many.

Interestingly, however, there was a revival in interest in Salieri's compositions because of the play and movie Amadeus. A lot of people realized the play was historically inaccurate, and what's more they realized that Salieri was actually an excellent composer. They started performing his works to prove it.

The real reason for the slander during Salieri's lifetime may have been his Italian ethnicity. At the time the Hapsburg Empire included much of Italy. But over time the German-speaking members of the Hapsburg Empire became more chauvinistic about their taste in music, and did not appreciate an Italian composer directing Italian operas in Vienna. That's true even though Salieri's own compositions were heavily influenced by German composers.