Mr. William Shakespeare's Comedies, Histories, & Tragedies is the 1623 published collection of William Shakespeare's plays. Modern scholars commonly refer to it as the First Folio. The First Folio is considered one of the most influential books ever published in the English language.
Printed in folio format and containing 36 plays (see list of Shakespeare's plays), it was prepared by Shakespeare's colleagues John Heminges and Henry Condell. It was dedicated to the "incomparable pair of brethren" William Herbert, 3rd Earl of Pembroke and his brother Philip Herbert, Earl of Montgomery (later 4th Earl of Pembroke).
Although 18 of Shakespeare's plays had been published in quarto before 1623, the First Folio is arguably the only reliable text for about 20 of the plays, and a valuable source text for many of those previously published. The Folio includes all of the plays generally accepted to be Shakespeare's, with the exception of Pericles, Prince of Tyre, The Two Noble Kinsmen, and the two lost plays, Cardenio and Love's Labour's Won.