Which best describes British civilization as Ishiguro portrays it in The Buried Giant?

Post-Arthurian civilization

Explanation:

The Buried Giant is a fantasy novel authored by award winning writer Kazuo Ishiguro.

The novel, which is based on fantasy talks about an elderly British couple who live in post-Arthurian times where the people do not have long term memories.

The names of the British couple were Axl and Beatrice. They can't be sure but they think they have a son but can't remember what became of him so they go on a journey to find him. From the novel, Saxons and Britons lived in peace together.

Axl and Beatrice go on an adventurous journey on their way to finding their son. They encounter a man named Sir Gawain who they are told was tasked with killing the dragon Querig by King Arthur many years ago but failed.

A visiting Saxon warrior Wistan rescues a boy named Edwin from ogres and he follows Axl and Beatrice on their quest to find their son (and to locate the dragon Querig and kill it).

Wistan, Sir Gawain goes with Axl and Beatrice to Querig's lair. It was later discovered that Sir Gawain was not tasked with killing the dragon but protecting its life. Wistan and Sir Gawain have a duel, Wistan kills him and proceeds to slay the dragon, thereby restoring the peoples memories and re-igniting enmity between the Saxons and Britons.