Hoaxes have long been a part of history, from the ancient Greeks to modern day. In celebration of April Fool's Day, count down with us some of the greatest moments of trickery known to man.

The Trojan Horse

Whether you believe the tale Virgil tells in "The Aenied" is fact or fiction, the Trojan Horse still stands as one of the greatest hoaxes known to history, real or literary. Legend has it that the Greeks, in a longstanding war against the Trojans, built a giant (and hollow) wooden horse and presented it to their rivals. After the Trojans willingly brought the peace offering into their fortified city, an army of Greeks burst out of the statue and effectively crushed the opposition, using what’s now considered to be one of the oldest tricks in the book.

"The War of the Worlds" Broadcast

On Halloween night, 1938, a radio broadcast of H.G. Wells’ 1898 science fiction novel "The War of the Worlds" had people convinced that aliens were invading the United States. The broadcast was orchestrated by the famous Orson Welles (pictured above, answering questions from the press the following day). Much of the show was in an “emergency bulletin” format. Those who tuned in mid-broadcast didn't recognize that they had stumbled upon a fictional show and instead thought they had tuned in just in time to hear emergency announcements that aliens were invading. Welles claimed he hadn't foreseen the hysteria. The event is still commemorated to this day in Grover’s Mill, N.J. (home to the “invasion”) by a stone monument.

The Piltdown Man

The Piltdown Man is literally the definition of hoax. In 1912, Charles Dawson and Arthur Smith Woodward unearthed a strange set of fossils in Sussex, England. These fragments would be pieced together to form the "Piltdown Man" skull and were famously hailed as proof of the "missing link" between humans and apes, according to the British Natural History Museum, which uses the incident as a prime example of "bad science." It would take 40 years, and the invention of better scientific dating, for the skull to be revealed as a fake. To this day, no one (or no group of individuals) has been identified as the mastermind behind the Piltdown Man hoax, although there have been theories.

U-505

In the midst of WWII, on June 4, 1944, the U.S. Navy captured the German submarine U-505 and kept it and its surviving crew members a secret. The Allied forces hoped to use the materials and code books found aboard the sub against the Nazis without the opposition knowing they had an upper hand. And it worked. U-505 was towed to Bermuda. The 58 Nazi soldiers captured during the raid were kept in relative isolation and not allowed to send letters from their imprisonment. The German army considered them dead, even sending notice to their families, according to Chicago’s Museum of Science and Industry, where the submarine currently is on exhibit to the public. The survivors were eventually released at the end of the war.

Balloon Boy

Perhaps once of history's most recent hoaxes, the plight of a young boy, Falcon Heene, supposedly launched (accidentally of course) into the Colorado skies in his family's UFO-like balloon, captured widespread media attention on Oct. 15, 2009. Heene would later be found safe and sound, hiding in his family's home. In a news interview the next day, young Falcon Heene would also accidentally mention it "was for the show," revealing the hoax. His parents, Richard and Mayumi Heene, admitted to orchestrating the entire incident for the publicity. They were fined and had to serve jail time.