Howard Pyle 
The Story of the Champions of the Round Table 
With linked Table of Contents

Sir Launcelot of the Lake dwelt within a magic lake which was the enchanted habitation of the Lady Nymue of the Lake. He was there trained in all the most excellent arts of chivalry by Sir Pellias, the Gentle Knight. All of this was told in this book and many other things concerning Sir Launcelot and several other worthies who were Companions of the Round Table and who were very noble and excellent knights both in battle and in court.