Short answers, pulled from the story.
A history play is a theatrical work based on a historical narrative, often set in the medieval or early modern past. It is one of the three main genres in Western theatre alongside tragedy and comedy, and it emerged as a distinct form in Renaissance England.
The history play took its modern form in Tudor England during the sixteenth century. Early examples include John Skelton's Magnyfycence from 1519 and John Bale's Kynge Johan, written in 1538.
Shakespeare's histories, organized as a separate category in the First Folio of 1623, cover English history from the reign of King John to Henry VIII, including the eight-play sequence known as the Henriad. Later playwrights either followed his stylistic model or worked in conscious awareness of their differences from it.
The Henriad is the name for Shakespeare's second tetralogy, finished in 1599, named after its central figure Prince Hal, the future Henry V. It includes Richard II, Henry IV Part 1, Henry IV Part 2, and Henry V.
Christopher Marlowe's Edward II, from 1592, was profoundly influential because Marlowe selected only events that served the story rather than trying to include all available historical information. This approach established a new link between history and tragedy and set a standard for using the history play as propaganda.
The earliest surviving play about a real event, The Persians, differs from the modern history play because it incorporates supernatural elements as fact and dramatizes the Persian reaction to the battle of Salamis rather than adopting the perspective a Greek historian would have taken. The modern history play requires a conception of history that excludes unverifiable supernatural elements.