Rome was once a largely democratic society, with regular elections. This Republic lasted for 500 years, but then came Tiberius Gracchus. He believed in the ideals of the Republic - fairness, decency and justice for everyone -but was appalled by Rome's aristocrats' treatment of the poor. So he unleashed the power of the mob upon the streets of Rome, with devastating consequences.

Julian Richards investigates the impact of the Vikings in Britain. This edition focuses on the archaeological trail left by the Vikings as they travelled from Norway along the sea road to Dublin. Settlements, a boat burial and evidence of trading have been discovered on the Scottish isles, and silver hoards found in Ireland suggest that Dublin was not only wealthy and important, but also a centre for trade in slaves.

The fantastical tale of King Arthur, the hero warrior, is one of the great themes of British literature. But was it just invented to restore British pride after the Norman invasion? Michael Wood puts the king in the spotlight.

The Red Sea is one of the youngest oceans in the world and one of the warmest. The northern region, with its diverse array of marine life, is one of the most visited dive locations on earth while the southern end remains virtually unexplored. It's a global hotspot for marine biology and an important trade route throughout human history, linking the trade goods of India and the Far East with the markets of Egypt and Europe.

Journey through the long-vanished corners of prehistoric North America, beginning when man first entered the vast, unspoiled continent some 14,000 years ago, in this appealing BBC documentary. Witness ancient beasts, mammoths, mastodons, giant bears, and sabre-toothed cats, and see the legacies each has passed to their modern successors. Computer animation and digital effects bring to life mammoths, saber-toothed cats, giant ground sloths, short-faced bears, glyptodonts, and a plethora of smaller animals in a lush Ice Age mosaic. Discoveries from sites across America are the basis for the reconstructions.

The journey continues into Asia, the world's greatest land mass, in a quest to discover how early hunter-gatherers managed to survive in one of the most inhospitable places on earth - the Arctic region of Northern Siberia. Alice also explores what may have occurred during human migration to produce Chinese physical characteristics, and considers a controversial claim about Chinese evolution: that the Chinese do not share the same African ancestry as other peoples.