The story of the Nazis' fighting retreat from the Baltic to the heart of Berlin.

Following a humiliating defeat at Stalingrad, Adolf Hitler demands a switch to Total War before launching arguably the biggest tank battle in history.

Hitler attacks Russia with the biggest invasion force in history, armed with mega-weapons.

This series unveils the engineering secrets of various iconic megastructures that went on to spark a technological revolution, ultimately changing warfare forever. The Nazis built some of the biggest and deadliest pieces of military hardware in history. Adolf Hitler hired men like Wernher von Braun, Ferdinand Porsche and Alfred Krupp to build huge terror machines, high-tech superguns and weapons of mass destruction.

A look at some of America's most important battles during World War II and the unprecedented innovation that occurred during the conflict that followed Pearl Harbor.

Before the advent of air transportation, trains played a vital role during times of war. In addition to transporting soldiers and supplies to the front lines, the locomotives served as mobile hospitals and were sometimes used as massive weapons on wheels. "Combat Trains" explores some of the machines and railways that helped change history dating back to the Civil War. The show uses archival footage and accounts from veterans to highlight the stories of engineering prowess that helped the soldiers do their jobs.

Stories of some of the greatest and deadliest submarine patrols of World War II.

An account of the high-risk operations to find Hitler and turn the tide of the WWII.

Former House Intelligence Committee Chairman Mike Rogers hosts this CNN original series, an eight-part look at complex true stories of America's covert operations. The newly declassified missions are recounted firsthand by agents from all 16 U.S. intelligence bureaus, providing viewers with unprecedented access to a secret world of espionage. The missions span time periods from Cold War-era Moscow to modern-day Iran, from the streets of 1980s Cuba to Beijing of today. Among the stories covered are the military's hunts for Iraq dictator Saddam Hussein and al-Qaida leader Abu Musab al-Zarqawi.

Some of the greatest warships have gone on to shape the history of the world and have even pushed their crews into unbelievable and incredible acts of bravery. Take a look at the very first submarine which is rumored to have lurked beneath New York harbor during the Revolutionary War, the smaller ships that rescued thousands from Dunkirk, or the destroyer in the Cuban Missile Crisis. Over the years, conflicts and wars have prompted extreme advances to ship designs and now they are faster, stronger, and smarter than ever before.