https://www.gamespot.com/articles/total-war-saga-thrones-of-britannia-release-date-a/1100-6456493/

Sega has revealed that the first installment in Creative Assembly's new Total War Saga brand, Thrones of Britannia will release for PC on April 18, 2018. This standalone return to the British Isles is set in a tumultuous and uncertain time period where Gaelic, Anglo-Saxon, and Viking factions are fighting for control.

Based on the potential success of this game, Sega and Creative Assembly have plans in making the Total War Saga a spin-off series that hones in on major conflicts spanning a couple hundred years, rather than the longer wars that the franchise is known for. Although no price point has been set, Sega and Creative Assembly said that it will be lower than the standard $60/£40 price point, reflective of the smaller, yet substantial content the Total War Saga games are designed to offer. That said, Thrones of Britannia will still be as feature-rich as any other Total War game, employing the franchise's familiar gameplay mechanics like Faction Politics, War Fervour, and Diplomacy.