Short answers, pulled from the story.
Henry V is believed to have been written circa 1599, based in part on an apparent allusion in the play to the Earl of Essex's campaign in Ireland, which began in late March 1599 and collapsed by late June of that year. The Chronicle History of Henry the fifth was entered into the Stationers' Register on the 14th of August 1600.
The St Crispin's Day Speech is Henry's rallying address to his outnumbered nobles before the Battle of Agincourt in Act IV. It includes the lines "we few, we happy few, we band of brothers," and is delivered the morning after Henry has wandered his camp in disguise trying to gauge his soldiers' true feelings.
According to the play, the French suffered ten thousand casualties. The English lost a Duke, an Earl, a knight, a squire, and, in Henry's account, "of all other, but five and twenty." Laurence Olivier changed the English figure in his 1944 film to "five and twenty score" because historians believed the actual toll was approximately six hundred.
The court was divided on the justification for Henry's invasion, but unanimously found him guilty on the killing of prisoners, applying what the judges called "the evolving standards of the maturing society." Justices Samuel Alito and Ruth Bader Ginsburg presided at the mock trial held in Washington, D.C. in March 2010.
Two major films adapt the play directly: Laurence Olivier's 1944 version, made as wartime propaganda, and Kenneth Branagh's 1989 version, which emphasises the horrors of war. A 2019 film, The King, starring Timothée Chalamet, draws on Henry IV Part I, Henry IV Part II, and Henry V together.
Tom Hiddleston played Henry V in the BBC's 2012 Hollow Crown television series. The production was directed by Thea Sharrock and produced by Sam Mendes, and was broadcast as part of the 2012 Cultural Olympiad coinciding with the Summer Olympics.