There are history books as in textbooks and any number of them will do the trick. I think the one I had was called "History of Theater" and had a red cover. It starts with the Greeks and goes from there.
If you're looking for American Theatre, try "Broadway" by Brooks Atkinson. That will take you up to the 50s and 60s when Broadway was the center of theatre in America, before the rise of regional theatre.
Atkinson was the longtime drama critic for the Times and as was written once, is the reason there is a Brooks Atkinson Theatre on Broadway.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher
The "Broadway The American Musical" book based on the PBS six hour series is fantastic. Filled with over 500 color illustrations. I highly reccomend it.
BSoBW2: I punched Sondheim in the face after I saw Wicked and said, "Why couldn't you write like that!?"
The theatre history book that I always have used was written by Oscar Brockett, it has been revived tons of times. The copy I own is from the 70's I think, and my boyfriend has a very recent copy.
the good old brockett, what a great book. Also Changing Stages by Richard Eyre and Nicholas Wright is a great book, based on a PBS special they did like 3 years ago. it the history of theatre in the 20th century in England and America. I learned alot about a great playwright from it, John Osborne. Look back in Anger, his most important play, ushered in the era of angry young men. I hope it get revived in 2006 its 50th anniversary.
I own "At this theatre" by Louis Botto. It is a playbill display book, and shows virtually every playbill from every broadway show during the 20th century. it is quite fascinating, and i would highly recommend it!