Fortress Britain With Alice Roberts | Preview (Channel 4)

Professor Alice Roberts, Professor Danielle George and Dr Onyeka Nubia tell the story of Britain's obsession with invasion through history.

In the first episode they explore Henry VIII's fear ofinvasion from Catholic Europe through the physical reminders that remain to this day. At her base in Walmer Castle, Alice gets her hands on a vast hoard of Tudor coins and a 500-year-old jousting scorecard, as she learns how Henry's greed and ambition led him to bankrupt the nation and lay the foundations for the modern secret service.

Danielle visits Henry's mighty castle at Deal and witnesses the awesome power of the cannons built to defend England, while Onyeka gets within touching distance of the iconic Mary Rose. Dir: Dominic Bowles, Exec Prod: Mark Downie; Prod Co: IWC Media

The full series will be available on All 4 following the transmission of this episode on Saturday 25th March.