Berowne Timeline and Summary

Berowne reluctantly agrees to the King's oath.
Rosaline arrives with the Princess of France, and Berowne falls in love with her.
Breaking his oath, he sends a love letter to Rosaline by way of Costard.
Berowne watches as all three of his compatriots recite the love letters they've written, then jumps out of his tree and scolds them for breaking their oaths.
Berowne pretends that he alone has not broken the oath. Little does he know that Costard is on his way with Berowne's treasonous love letter.
Arguing passionately for the value of love, Berowne convinces his friends to abandon their vow.
Dressed like a Russian, Berowne unknowingly sweet-talks the Princess (believing her to be Rosaline). He's mad when he finds out the women's identity.
When Rosaline has to leave for France due to the King's death, she makes Berowne promise to spend a year as comedian for the sick.