The prized possessions of some of history's richest people haven't been castles, jewels or fine art. They've been something more exotic, endangered even, with the ability to bite back.

By the 1990s, synthetic voices for computers and the disabled were mostly male until researcher Ann Syrdal helped develop the first functional female synthetic voice, paving the way for AI assistants like Siri.

Learn how true darkness surrounded the cast and crew of the first-ever vampire film, "Nosferatu".

The flowering of the Roman Empire saw incomparable power and civilization—and at the same time corruption, cruelty and depravity on an unparalleled scale.

The first half of the 20th century saw massive surges in polio cases, resulting in extended hospital stays for many, including Eleanor Abbott, a retired schoolteacher who invented Candy Land to entertain the children she met in the polio ward.

Could history's two most notorious killers actually be the same man? Two experts investigate the theory that H.H. Holmes, America's first serial killer, was also Britain's Jack the Ripper.

St. Patrick's Day in 1776 was more than just an Irish-American celebration... it was also a step towards freedom.

This __Biography__ special travels to the 5th century to explore St. Patrick's transformation from privileged aristocrat to tormented slave to missionary hero.