Some history here in the title:
“Errant,” meaning wandering or roving, indicates how the knight-errant would typically wander the land in search of adventures to prove himself as a knight.
Many knights-errant fit the ideal of the “knight in shining armor”. To modern-day readers, the figure of the knight-errant suggests a sort of lawful or righteous vigilante. A knight-errant typically performed all his deeds in the name of a lady, and invoked her name before performing an exploit. In more sublimated forms of knight-errantry, pure metaphysical idealism rather than romantic inspiration motivated the knight-errant (as in the case of Sir Galahad). Such a knight might well be outside the structure of feudalism, wandering solely to perform noble exploits (and perhaps to find a lord to give his service to), but might also be in service to a king or lord, traveling either in pursuit of a specific duty that his overlord charged him with, or to put down evildoers in general.
This quest sends a knight on adventures much like the ones of a knight in search of them, as he happens on the same marvels. In The Faerie Queen, St. George is sent to rescue Una’s parents’ kingdom from a dragon, and Guyon has no such quest, but both knights encounter perils and adventures.
In the romances, his adventures frequently included greater foes than other knights, including giants, enchantresses, or dragons. They may also gain help that is out of ordinary. Sir Ywain assisted a lion against a serpent, and was thereafter accompanied by it, becoming the Knight of the Lion. Other knights-errant have been assisted by wild men of the woods, as in Valentine and Orson, or, like Guillaume de Palerme, by wolves that were, in fact, enchanted princes.
In Russian culture:
The Russian bylina feature bogatyrs, knights-errant who served as protectors of their homeland, and occasionally as adventurers. Some of them are presumed to be historical figures, while others are fictional and possibly descend from Slavic mythology. Most tales about bogatyrs revolve around the court of Vladimir I of Kiev. Three popular Russian knights—Ilya Muromets, Dobrynya Nikitich and Alyosha Popovich (famously painted by Victor Vasnetsov)—are said to have served him.
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