Medieval chant....monophonic
Renaissance masses/madrigals Polyphonic
Baroque...mix of homophonic and polyphonic
Classical....homophonic
Romantic....more homophonic than polyphonic
Edit: When answering the question, I tried to give an overview of an entire period. I qualified the Renaissance with its many masses and madrigals as being written in polyphonic style because of the many overlapping melodic lines....masses for divided choirs. These are the surely the major compositional efforts of the era rather than the simpler renaissance dances. The Baroque era with its many contrapuntal keyboard and vocal compositions by Handel and Bach was so important that late 18th century composers such as Mozart studied their works to gain the skill of writing in polyphony. Hence the few fugues written by Mozart. Handel's opera and oratorio arias were homophonic in style but his great choruses often were written in polyphony.
The classical era was more homophonic than polyphonic. I just stated that Mozart studied the works of Bach to learn contrapuntal composition and he used it on occasion, but he is not a good example of a composer who writes frequently in polyphony.
In the Romantic era, the over-all use of polyphony was slight. One doesn't think of the 19th century as the century of fugues and canons. Wagner wrote in a polyphonic style in his Meistersinger overture to show that he was capable of writing in such a learned form, but again, you wouldn't point to the works of Wagner as great examples of polyphony any more than you would Tchaikovsky or Brahms.