"Oliver Cromwell" is a book written by the famous American politician and writer Theodore Roosevelt. In this book, the author examines the life and activities of one of the greatest political leaders in English history, Oliver Cromwell. He talks about Cromwell's role in the English Revolution, his influence on the politics and society of that time. The book allows the reader to better understand the historical context in which Cromwell acted, his character and weaknesses. "Oliver Cromwell" is a fascinating journey into the past, which will help to better understand and appreciate the achievements of this outstanding figure.