Agatha Christie is a legend in the cozy mystery genre.
Agatha Chrisite's books have sold over a billion copies in English and another billion in one hundred foreign countries. She is the author of 80 novels and short-story collections and 19 plays. She wrote 6 novels under the name Mary Westmacott. Agatha died in 1976.
I can't think of another author whose clever plot invites you into English village life and offers such interesting clues and eccentric characters. When I want to read a cozy mystery I always chose a series that boasts that they have a bit of Agatha Christie style in them. I chose a website for Agatha Christie that I thought offered great insight into the author and her books so please feel free to check it out.
Agatha wrote several cozy mysteries. The Miss Marple Mystery series started in 1930 and is set in England. It features the famous spinster Miss Jane Marple who is a clever amateur sleuth and in the end out foxes every one.
She also wrote the Hercule Poirot Mystery Series which started in 1920 and is set in England. It features Belgian, Private Investigator, Hercule Poirot.
I am only listing books from these two series however please visit the website to learn about all of Agatha Christie's works.