Today's free book is Old English tales retold by Harriet B. Barbour (1928) with illustrations by Rodney Thomson. For the table of contents, check at the bottom of this post below the image.
The book is available at Hathi (I have not checked for other online sources).
Table of Contents
Beowulf
Havelok the Dane
The Adventures of Horn
Guy of Warwick
Bevis of Hampton
The Prince in Exile
Emarie
King Orpheo and the Fairies
The Strange Quest
Sir Launfal and the Fairy Princess
The Knight with the Lion
The Marriage of Sir Gawain