King Arthur was known to be an excellent king, fair and just.
Arthurian Legend usually refers to basic Medieval stories such as the Sword in the Stone. It also involves many interesting lives of the people who lived in Camelot, Avalon, etc. such as Mordred, Lady of the Lake, Sir Lancelot, Morgan le Fay, and more. Where wizards, and sorceresses roamed the land, and where dragons existed not only in the imagination.
The Round Table is also a common reference, as is the Excalibur.
Arthurian times takes place in Medieval Britain.