This book appears to be the personal journal of Lord Carwin from before the Mathosian Civil War.
Lord Carwin would later become a great general under his half brother, Prince Zareph, fighting against the evil forces of Zareph's brother, King Aedraxis. Lord Carwin was also the founder of the Sanctuary Guard. The knights at Heroes' Stand would be very interested in this find.
By Carwin's Hammer, this is an incredible find! How did you even notice this old tome among the rest of the ruins? My friend, the Vigil guides your hand; there can be no doubt.