How old is Shakespeare's oldest play?

Answer 1

Well, all of Shakespeare's plays were written more or less between 1590 and 1613. We don't have an exact date for his first play, but 1590 is an approximation. (There is a reference to one of the plays in 1592, so it had to have been written earlier. And there may have been others before that one.)

Answer 2

Circa 1580 - 1590 the Taming of the Shrew is considered to be one of Shakespeare's earliest works, the play is generally believed to have been written before 1592