The King of Navarre and his courtiers Berowne and Dumaine vow to pursue a monastic life devoted to study, swearing off all contact with women for three years.
Berowne predicts this vow is destined to fail, for it is “flat treason ‘gainst the kingly state of youth.” The plan “not to see ladies, study, fast, not sleep” goes awry when the Princess of France and her attendants Rosaline and Katharine arrive as ambassadors on political business. The men are besotted, the women bemused, and a lively battle between the sexes ensues. Into this mix comes another love-tangle: the fantastical Spaniard Don Armado is in love with the maid Jaquenetta, who is also wooed by the rustic clown Costard.
A bit of history from the Folger Shakespeare Library
Love's Labour's Lost was written before 1598 – the first Quarto edition of that year refers to the play being 'presented before her Highness [Queen Elizabeth] this last Christmas'. A poem by Robert Tofte in 1598 also refers to a performance seen in a theatre. Stylistically similar to A Midsummer Night's Dream and other lyrical plays, most scholars date the composition to 1595-96.
Unusually, Love's Labour's Lost seems to have no principal literary source, though draws in many aspects of literary culture of the early 1590s. The idea of ... courtiers retreating from everyday life to engage in academic reflection may have been inspired by Pierre de la Primaudaye's The French Academy (English translation in 1586). The pageants within the play – the Muscovites, the Nine Worthies... – all derive from the tradition of royal entertainments and progresses of the time.