What Shakespeare play begins with the line, "Now is the winter of our discontent"?

"Now is the winter of our discontent, made glorious summer by this sun of York" are opening lines in William Shakespeare's play, Richard III. It forms the groundwork for Shakespeare's portrait of King Richard in 1594. Shakespeare presents an account of Richard's character that (until the late 20th century) viewed him largely in popular terms as a malevolent and deformed schemer. He was seen as a very hateful man.

At the time, Richard's representation was used in this play as a dramatic plot device. It was Shakespeare’s eponymous play, written 106 years after Richard’s death, that cemented the King’s bad reputation. Now it is not consistent with what is known of King Richard III. During his reign, he was an enlightened and forward-looking monarch. His good works included significant changes to English law, including the presumption of ‘innocent until proven guilty’ and a reformation of the jury system.

But the opening words of this play are used to clearly portray Richard as a discontented man, who is unhappy in a world that hates him. Shakespeare views him as "Deformed, unfinished, sent before his time into this breathing world, scarce half made up". He says that if he "cannot prove a lover" he is "determined to be a villain". Shakespeare never stated that he actually believed the propaganda against Richard. He only uses it for dramatic effect. Also, no historical experts ever publicly acknowledge or generally accept any of the propaganda against King Richard III.