Created by James Richardson and brothers Tom and Jez Butterworth, the latest series will return to ancient Britannia where Cait, played by Eleanor Worthington-Cox, is carrying out her prophecy as the ‘Chosen One’ who will save her war-torn land of Druids and Celts from the Romans.

Having now spent two years organising the invasion in Britannia, the Roman General Aulus (David Morrissey) is faced with a new dark and domineering force, his wife. The Celtic Queen Amena (Annabel Scholey) becomes unwillingly involved in a deadly ménage à trois between them.

Meanwhile, the terrifying Druid leader Veran (Mackenzie Crook) travels to the underworld to envision the future.

Writer Jez Butterworth said: “We’re very excited to be continuing our mythic journey through Ancient Britain.

“This year was a particularly good vintage for mushrooms here in the West Country, so we strongly suggest you hold on to your hats.”

The third series of Britannia will be shown on Sky Atlantic and Now TV.