A good introductory book is Peter N. Stearns and Susan J. Matt, Doing Emotions in History (Urbana, 2004), which offers summaries of main ideas.

Jan Plamper, The History of Emotions: An Introduction (Oxford, 2015) is also a good book, and might be more interesting. But have a look at the contents of both if you're planning to buy rather than borrow.

If you'd like to go straight to reading the theory rather than intros, I'd have a look at the works of these authors: Peter N. Stearns and Carol Z. Stearns (emotionology); William Reddy (emotives, emotional regimes); Barbara Rosenwein (emotional communities); Norbert Elias (civilising process).

Edit: The aforementioned authors have books where they talk about emotion in history, rather than just simply books full of theory -- which is why I suggest names. E.g., Stearns and Stearns, Anger: The Struggle for Emotional Control in America's History (Chicago, 1987).