The second World War had a profound effect on the course of the 20th century, and unfortunately, its horrors, including "ethnic cleansing," terrorism, despotism, invasions, the curtailment of civil rights, and rampant nationalism, are still concerns of the modern day. The documentary series The World at War is outstanding in its ability to unfold the complex issues of WWII in a clear, objective, and gripping manner.
Each of the 26 episodes of this five-DVD set, narrated by Laurence Olivier, focuses on a particular, specific aspect of the war, starting at the beginning with Hitler's rise to power in Germany and progressing through the end of the war. Because of this focus, each episode examines its subject in detail, going beyond the names-and-dates style of history that I remember being subjected to in high school, to delve into the much more interesting and important issues of "how and why."
I learned something new from every single episode, starting with the very first one. The episodes proceed overall on a regular timeline from the beginning to the end of the war, but since a great deal often happened over a short period of time, the series backtracks at several points to fill in what was happening in different places. For instance, after we are taken through the events from Hitler's rise to power in Germany in the late 1930s to the Battle of Britain and Hitler's attacks on Russia.