William Shakespeare's play Henry V is heavily indebted to its historical sources. To gain a complete understanding of the play one must have some knowledge of the time period of the play as well as its historical figures and references it contains. Here are some of Shakespeare's primary sources he used when writing the play...............................
*The primary source was Raphael Holinshed's Chronicles of England, Scotland, and Ireland (1577)
*Edward Hall's The Union of the Two Noble and Illustre Families of Lancaster and York (1548)
*An anonymous play entered by Stationers' Register on May 14, 1594 with the title The Famous Victories of Henry V; Containing the Honourable Battel of Agin-court. This play suggests several incidents and the possibilities of a realistic, comic sub-plot.
**Also..... since Henry V is the last play of Shakespeare's tetralogy, it may be a good idea to have read or at least know an overview of the following Shakespeare plays (I have provided links to all of these for your convenience):
Henry IV, Part !
Henry IV, Part 2