Giants (aka, Cewri in Welsh) are mythological entities prominently found in Welsh lore.
The first mention of giants in the RTC world is in the prologue of book one, where it is said that giants once ruled the land and Arthur and his knights killed them all.
Giants are primarily known for and recognized by their immense size. Folklore credits them with carving out the distinctive cliffs found along the southern coast of Great Britain - a testament to their incredible strength as well as their stature. They are not known for their beauty, though beyond these details, their appearance can range greatly from story to story.
RTC book 1 mentions giants in the prologue as noted above.
Arthur and his knights are credited with slaughtering a number of named giants in Welsh lore. Such tales are demonstrative of just how powerful these men were, since they could fell some of the most powerful and despicable creatures of the land.
Links to stories/summaries