h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Yes, you don't want to base your understanding of history on Shakespeare. Most of his histories were based on dubious sources and the ones dealing with more recent history are propaganda.

I've heard that Henry V wasn't the sort of man who went around giving great speeches. Instead, he lived and fought alongside his men, knew what weapons they needed and made sure they got them. So he probably said something like "OK lads, let's give it to them!"

You're absolutely right! At least, according to the chroniclers. Here's Holinshed's version, which presumably was the source for Shakespeare's fancier text:

http://zsr.wfu.edu/2015/a-source-for-shakespeares-history/

But there's at least one other lie in that play, too - it concerns the question of who may, or may not, have committed a war crime...