Borrow or purchase a good textbook on England's history. A recently published textbook is preferred, as it would capture all the new archeological and other findings that may shed additional light on some of the periods in the history of England
Use the link in the Resources section of this article to read about English history. There are many other resources available on the Web.
Learn about prehistoric and Roman Britain. Before the Romans came to England in A.D. 43, the land was primarily populated by Celtic tribes. However, after the Romans were forced to leave in the fifth century, the British Isles were conquered by Anglo-Saxon tribes.
Study medieval Britain, including the Reformation and Restoration and the time of the British Empire. English monarchs played a particularly important part at that time, so pay attention to the the royal dynasties. Learn how England was invaded by William the Conqueror in the 11th century and how it influenced the English language. Also, study how Great Britain spread its influence around the world, reaching military and economic superiority in the middle of the 19th century.
Learn 20th century and contemporary English history. Study how England and its huge empire fought Germany in two world wars, and how that empire came apart. Also, learn about the cross-Atlantic relationship between the U.K. and the U.S., which defined England's post-war history.