Timewatch Season 23 Episode release dates & where to watch

1. Britain's X-Files

Examining the UFO phenomenon in Britain since the 1950s, when alleged sightings began and Clement Attlee formed the Flying Saucer Working Party. The documentary recalls how UFOs became a symbol of the communist threat during the Cold War and - with access to previously secret files - shows how paranoia over these mysterious vessels struck at the heart of the political, military, and royal establishments. NEW SERIES 1/5.

2. The Lost Liner and the Empire's Gold

On 30 December 1915 the Persia, a passenger ship loaded with gold bullion bound for Bombay, was torpedoed by the notorious U-boat ace Max Valentiner, killing over ## people and sending the liner to the bottom of the sea. For 88 years, the wreck's whereabouts has remained a mystery. However, salvage experts Moya and Alec Crawford believe they can locate the Persia - and her precious cargo. 2/5.

3. The Secrets of Enzo Ferrari

Glamour, money, sex, and danger are all synonymous with the Ferrari brand, and all were evident in the life of its creator, who died in 1988. He was prepared to manipulate, test, and shape everyone around him to achieve his dream. But he also led a secretive life - explored here. 3/5.

4. The Mysteries of the Medieval Ship

The well-preserved remains of an 80ft medieval merchant ship came to light in 2002 on the banks of the River Usk in Newport, Gwent. Two of the archaeologists involved - Kate Hunter and Nigel Nayling - delve into its history, uncovering secrets dating back to the Wars of the Roses. 4/5.

5. How Mad Was King George?

He's best known for having suffered bouts of mental illness and losing the American colonies, but what was King George III really like? With contributions from the Prince of Wales, Timewatch re-examines the life of Britain's longest-reigning king who, despite a painful metabolic condition, was a dutiful, plain-living monarch whose 60 years on the throne saw a flowering of the arts and sciences. 5/5.

6. Who Killed Rasputin?

Could the British Secret Service be linked with a murder that, for nearly 90 years, has been attributed to self-confessed culprit Prince Felix Yusupov? Acting with a group of fellow conspirators, he is said to have poisoned, shot, and finally drowned the allegedly mad monk Grigori Rasputin in the Russian city of St Petersburg in 1916. Former Scotland Yard commander and murder detective Richard Cullen travels back to the scene of the crime to re-examine the evidence. NEW SERIES 1/6.

7. The Lost Heroes

When a handful of British volunteers were pitted against the might of the German battleship Tirpitz in 1943, official records described the raid as the most daring attack of the Second World War. Four-man X-class midget submarines battled for 11 days across arctic seas to the impregnable Norwegian fjord where Germany's biggest ship awaited them. While crew members from two of the vessels survived, mystery has always surrounded the role of the X5's crew. Now a team of divers seeks out the truth in order to reveal the story of the unsung heroes. 2/6.

8. The Mystery of the Black Death

Could the Black Death - killer of up to half of Europe in the 14th century - be lying dormant, ready to strike again? New evidence refutes received opinion that the cause was bubonic plague spread by rats, but was actually a deadly virus that emerged from animals and then vanished again. 3/6.

9. The Black Pharaohs

Could a set of hieroglyphs be about to change the face of Ancient Egypt for ever? Doctor Viv Davies claims that this recent discovery proves that in 800 BC, Egypt was under the rule of 'black Pharaohs' from neighbouring Nubia. As the British Museum prepares an international exhibition of additional finds that seem to corroborate his assertion, this programme accompanies Doctor Davies on his final digs to unearth more clues to the lives of these long-forgotten rulers. 4/6.

10. The Secrets of the Mary Rose

The story of the men who served on board the Tudor warship, which sank in Portsmouth harbour during a battle with French forces. Archaeological analysis of artefacts recovered from the wreck, reconstructions, and computer graphics combine to lay bare 16th-century naval life. 5/6.

11. Julius Caesar's Greatest Battle Finale

A journey through modern France in the footsteps of Julius Ceasar. Reconstructions provide an insight into the climax of Caesar's bloody eight-year conflict in Gaul. The great siege at Alesia in 52 BC would seal Gaul's fate and shape the future of the Western world. 6/6.