Sir Bedivere

The knight who tended to King Arthur’s last moments.
The last knight, who returned the holy sword to the lake by his king’s decree.
The mention of King Arthur’s knights brings to mind names like Lancelot, Percival, and Galahad, but they are actually relative newcomers, recruited specifically for the holy grail quest.
Of the knights who accompanied King Arthur from the very beginning, the most famous are Sir Kay, Sir Gawain, and of course, Sir Bedivere. In fact, they possess histories even longer than King Arthur himself.
The model of Sir Bedivere is thought to be the ancient Celtic warrior, Bedwyr.
Oh, and this is just a digression, but he never realized that Artoria was a girl.

Fate/side material: Fate Encyclopedia